ruff_python_formatter: add support for docstring code "dynamic" mode

This computes the line width to use on the nested call to the
formatter based on the current indent level, indent width and
configured global setting.

Ref #8855

crates/ruff_python_formatter/src/expression/string/docstring.rs

@@ -7,13 +7,13 @@ use std::{borrow::Cow, collections::VecDeque};
 use {once_cell::sync::Lazy, regex::Regex};
 
 use {
-    ruff_formatter::{write, IndentStyle, Printed},
+    ruff_formatter::{write, FormatOptions, IndentStyle, LineWidth, Printed},
     ruff_python_trivia::{is_python_whitespace, PythonWhitespace},
     ruff_source_file::Locator,
     ruff_text_size::{Ranged, TextLen, TextRange, TextSize},
 };
 
-use crate::{prelude::*, FormatModuleError};
+use crate::{prelude::*, DocstringCodeLineWidth, FormatModuleError};
 
 use super::{NormalizedString, QuoteChar};
 
@@ -460,11 +460,22 @@ impl<'ast, 'buf, 'fmt, 'src> DocstringLinePrinter<'ast, 'buf, 'fmt, 'src> {
             .map(|line| line.code)
             .collect::<Vec<&str>>()
             .join("\n");
+        let line_width = match self.f.options().docstring_code_line_width() {
+            DocstringCodeLineWidth::Fixed(width) => width,
+            DocstringCodeLineWidth::Dynamic => {
+                let global_line_width = self.f.options().line_width().value();
+                let indent_width = self.f.options().indent_width();
+                let indent_level = self.f.context().indent_level();
+                let current_indent = indent_level.to_ascii_spaces(indent_width);
+                let width = std::cmp::max(1, global_line_width.saturating_sub(current_indent));
+                LineWidth::try_from(width).expect("width is capped at a minimum of 1")
+            }
+        };
         let options = self
             .f
             .options()
             .clone()
-            .with_line_width(self.f.options().docstring_code_line_width())
+            .with_line_width(line_width)
             // It's perhaps a little odd to be hard-coding the indent
             // style here, but I believe it is necessary as a result
             // of the whitespace normalization otherwise done in