Avoid flagging __future__ annotations as required for non-evaluated…

… type annotations (#11414)

## Summary

If an annotation won't be evaluated at runtime, we don't need to flag
`from __future__ import annotations` as required. This applies both to
quoted annotations and annotations outside of runtime-evaluated
positions, like:

```python
def main() -> None:
    a_list: list[str] | None = []
    a_list.append("hello")
```

Closes #11397.

crates/ruff_linter/resources/test/fixtures/flake8_future_annotations/ok_quoted_type.py

@@ -0,0 +1,7 @@
+def main() -> None:
+    a_list: list[str] | None = []
+    a_list.append("hello")
+
+
+def hello(y: "dict[str, int] | None") -> None:
+    del y

crates/ruff_linter/src/checkers/ast/analyze/expression.rs

@@ -62,6 +62,8 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
                 if !checker.semantic.future_annotations_or_stub()
                     && checker.settings.target_version < PythonVersion::Py39
                     && checker.semantic.in_annotation()
+                    && checker.semantic.in_runtime_evaluated_annotation()
+                    && !checker.semantic.in_string_type_definition()
                     && typing::is_pep585_generic(value, &checker.semantic)
                 {
                     flake8_future_annotations::rules::future_required_type_annotation(
@@ -1195,6 +1197,8 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
                 if !checker.semantic.future_annotations_or_stub()
                     && checker.settings.target_version < PythonVersion::Py310
                     && checker.semantic.in_annotation()
+                    && checker.semantic.in_runtime_evaluated_annotation()
+                    && !checker.semantic.in_string_type_definition()
                 {
                     flake8_future_annotations::rules::future_required_type_annotation(
                         checker,

crates/ruff_linter/src/rules/flake8_future_annotations/mod.rs

@@ -43,6 +43,7 @@ mod tests {
     #[test_case(Path::new("no_future_import_uses_union_inner.py"))]
     #[test_case(Path::new("ok_no_types.py"))]
     #[test_case(Path::new("ok_uses_future.py"))]
+    #[test_case(Path::new("ok_quoted_type.py"))]
     fn fa102(path: &Path) -> Result<()> {
         let snapshot = format!("fa102_{}", path.to_string_lossy());
         let diagnostics = test_path(

crates/ruff_linter/src/rules/flake8_future_annotations/snapshots/ruff_linter__rules__flake8_future_annotations__tests__fa102_no_future_import_uses_lowercase.py.snap

@@ -1,21 +1,6 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_future_annotations/mod.rs
 ---
-no_future_import_uses_lowercase.py:2:13: FA102 [*] Missing `from __future__ import annotations`, but uses PEP 585 collection
-  |
-1 | def main() -> None:
-2 |     a_list: list[str] = []
-  |             ^^^^^^^^^ FA102
-3 |     a_list.append("hello")
-  |
-  = help: Add `from __future__ import annotations`
-
-ℹ Unsafe fix
-  1 |+from __future__ import annotations
-1 2 | def main() -> None:
-2 3 |     a_list: list[str] = []
-3 4 |     a_list.append("hello")
-
 no_future_import_uses_lowercase.py:6:14: FA102 [*] Missing `from __future__ import annotations`, but uses PEP 585 collection
   |
 6 | def hello(y: dict[str, int]) -> None:
@@ -29,5 +14,3 @@ no_future_import_uses_lowercase.py:6:14: FA102 [*] Missing `from __future__ impo
 1 2 | def main() -> None:
 2 3 |     a_list: list[str] = []
 3 4 |     a_list.append("hello")
-
-

crates/ruff_linter/src/rules/flake8_future_annotations/snapshots/ruff_linter__rules__flake8_future_annotations__tests__fa102_no_future_import_uses_union.py.snap

@@ -1,36 +1,6 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_future_annotations/mod.rs
 ---
-no_future_import_uses_union.py:2:13: FA102 [*] Missing `from __future__ import annotations`, but uses PEP 585 collection
-  |
-1 | def main() -> None:
-2 |     a_list: list[str] | None = []
-  |             ^^^^^^^^^ FA102
-3 |     a_list.append("hello")
-  |
-  = help: Add `from __future__ import annotations`
-
-ℹ Unsafe fix
-  1 |+from __future__ import annotations
-1 2 | def main() -> None:
-2 3 |     a_list: list[str] | None = []
-3 4 |     a_list.append("hello")
-
-no_future_import_uses_union.py:2:13: FA102 [*] Missing `from __future__ import annotations`, but uses PEP 604 union
-  |
-1 | def main() -> None:
-2 |     a_list: list[str] | None = []
-  |             ^^^^^^^^^^^^^^^^ FA102
-3 |     a_list.append("hello")
-  |
-  = help: Add `from __future__ import annotations`
-
-ℹ Unsafe fix
-  1 |+from __future__ import annotations
-1 2 | def main() -> None:
-2 3 |     a_list: list[str] | None = []
-3 4 |     a_list.append("hello")
-
 no_future_import_uses_union.py:6:14: FA102 [*] Missing `from __future__ import annotations`, but uses PEP 585 collection
   |
 6 | def hello(y: dict[str, int] | None) -> None:
@@ -58,5 +28,3 @@ no_future_import_uses_union.py:6:14: FA102 [*] Missing `from __future__ import a
 1 2 | def main() -> None:
 2 3 |     a_list: list[str] | None = []
 3 4 |     a_list.append("hello")
-
-

crates/ruff_linter/src/rules/flake8_future_annotations/snapshots/ruff_linter__rules__flake8_future_annotations__tests__fa102_no_future_import_uses_union_inner.py.snap

@@ -1,36 +1,6 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_future_annotations/mod.rs
 ---
-no_future_import_uses_union_inner.py:2:13: FA102 [*] Missing `from __future__ import annotations`, but uses PEP 585 collection
-  |
-1 | def main() -> None:
-2 |     a_list: list[str | None] = []
-  |             ^^^^^^^^^^^^^^^^ FA102
-3 |     a_list.append("hello")
-  |
-  = help: Add `from __future__ import annotations`
-
-ℹ Unsafe fix
-  1 |+from __future__ import annotations
-1 2 | def main() -> None:
-2 3 |     a_list: list[str | None] = []
-3 4 |     a_list.append("hello")
-
-no_future_import_uses_union_inner.py:2:18: FA102 [*] Missing `from __future__ import annotations`, but uses PEP 604 union
-  |
-1 | def main() -> None:
-2 |     a_list: list[str | None] = []
-  |                  ^^^^^^^^^^ FA102
-3 |     a_list.append("hello")
-  |
-  = help: Add `from __future__ import annotations`
-
-ℹ Unsafe fix
-  1 |+from __future__ import annotations
-1 2 | def main() -> None:
-2 3 |     a_list: list[str | None] = []
-3 4 |     a_list.append("hello")
-
 no_future_import_uses_union_inner.py:6:14: FA102 [*] Missing `from __future__ import annotations`, but uses PEP 585 collection
   |
 6 | def hello(y: dict[str | None, int]) -> None:
@@ -60,35 +30,3 @@ no_future_import_uses_union_inner.py:6:19: FA102 [*] Missing `from __future__ im
 1 2 | def main() -> None:
 2 3 |     a_list: list[str | None] = []
 3 4 |     a_list.append("hello")
-
-no_future_import_uses_union_inner.py:7:8: FA102 [*] Missing `from __future__ import annotations`, but uses PEP 585 collection
-  |
-6 | def hello(y: dict[str | None, int]) -> None:
-7 |     z: tuple[str, str | None, str] = tuple(y)
-  |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ FA102
-8 |     del z
-  |
-  = help: Add `from __future__ import annotations`
-
-ℹ Unsafe fix
-  1 |+from __future__ import annotations
-1 2 | def main() -> None:
-2 3 |     a_list: list[str | None] = []
-3 4 |     a_list.append("hello")
-
-no_future_import_uses_union_inner.py:7:19: FA102 [*] Missing `from __future__ import annotations`, but uses PEP 604 union
-  |
-6 | def hello(y: dict[str | None, int]) -> None:
-7 |     z: tuple[str, str | None, str] = tuple(y)
-  |                   ^^^^^^^^^^ FA102
-8 |     del z
-  |
-  = help: Add `from __future__ import annotations`
-
-ℹ Unsafe fix
-  1 |+from __future__ import annotations
-1 2 | def main() -> None:
-2 3 |     a_list: list[str | None] = []
-3 4 |     a_list.append("hello")
-
-

crates/ruff_linter/src/rules/flake8_future_annotations/snapshots/ruff_linter__rules__flake8_future_annotations__tests__fa102_ok_quoted_type.py.snap

@@ -0,0 +1,4 @@
+---
+source: crates/ruff_linter/src/rules/flake8_future_annotations/mod.rs
+---
+