Use a sorted vector for block comments (#9337)

## Summary

I realized that we can avoid allocating a hash map here.

crates/ruff_linter/src/rules/pylint/rules/empty_comment.rs

@@ -2,10 +2,8 @@ use ruff_diagnostics::{Diagnostic, Edit, Fix, FixAvailability, Violation};
 use ruff_macros::{derive_message_formats, violation};
 use ruff_python_index::Indexer;
 use ruff_python_trivia::is_python_whitespace;
-
 use ruff_source_file::Locator;
 use ruff_text_size::{TextRange, TextSize};
-use rustc_hash::FxHashSet;
 
 /// ## What it does
 /// Checks for a # symbol appearing on a line not followed by an actual comment.
@@ -50,11 +48,11 @@ pub(crate) fn empty_comments(
     indexer: &Indexer,
     locator: &Locator,
 ) {
-    let block_comments = FxHashSet::from_iter(indexer.comment_ranges().block_comments(locator));
+    let block_comments = indexer.comment_ranges().block_comments(locator);
 
     for range in indexer.comment_ranges() {
         // Ignore comments that are part of multi-line "comment blocks".
-        if block_comments.contains(&range.start()) {
+        if block_comments.binary_search(&range.start()).is_ok() {
             continue;
         }
 

crates/ruff_python_trivia/src/comment_ranges.rs

@@ -54,8 +54,8 @@ impl CommentRanges {
     /// own-line comments in which the comment hash (`#`) appears in the same
     /// column in each line, and at least one comment is non-empty.
     ///
-    /// Returns a vector containing the offset of the leading hash (`#`) for
-    /// each comment in any block comment.
+    /// Returns a sorted vector containing the offset of the leading hash (`#`)
+    /// for each comment in any block comment.
     ///
     /// ## Examples
     /// ```python