Format trailing operator comments as dangling (#7427)

## Summary

Given a trailing operator comment in a unary expression, like:

```python
if (
  not  # comment
  a):
    ...
```

We were attaching these to the operand (`a`), but formatting them in the
unary operator via special handling. Parents shouldn't format the
comments of their children, so this instead attaches them as dangling
comments on the unary expression. (No intended change in formatting.)

crates/ruff_python_formatter/src/comments/placement.rs

@@ -208,6 +208,7 @@ fn handle_enclosed_comment<'a>(
         AnyNodeRef::PatternKeyword(pattern_keyword) => {
             handle_pattern_keyword_comment(comment, pattern_keyword, locator)
         }
+        AnyNodeRef::ExprUnaryOp(unary_op) => handle_unary_op_comment(comment, unary_op, locator),
         AnyNodeRef::ExprNamedExpr(_) => handle_named_expr_comment(comment, locator),
         AnyNodeRef::ExprDict(_) => handle_dict_unpacking_comment(comment, locator)
             .or_else(|comment| handle_bracketed_end_of_line_comment(comment, locator)),
@@ -1583,6 +1584,46 @@ fn handle_named_expr_comment<'a>(
     }
 }
 
+/// Attach trailing end-of-line comments on the operator as dangling comments on the enclosing
+/// node.
+///
+/// For example, given:
+/// ```python
+/// (
+///     not  # comment
+///     True
+/// )
+/// ```
+///
+/// The `# comment` will be attached as a dangling comment on the enclosing node, to ensure that
+/// it remains on the same line as the operator.
+fn handle_unary_op_comment<'a>(
+    comment: DecoratedComment<'a>,
+    unary_op: &'a ast::ExprUnaryOp,
+    locator: &Locator,
+) -> CommentPlacement<'a> {
+    if comment.line_position().is_own_line() {
+        return CommentPlacement::Default(comment);
+    }
+
+    if comment.start() > unary_op.operand.start() {
+        return CommentPlacement::Default(comment);
+    }
+
+    let tokenizer = SimpleTokenizer::new(
+        locator.contents(),
+        TextRange::new(comment.start(), unary_op.operand.start()),
+    );
+    if tokenizer
+        .skip_trivia()
+        .any(|token| token.kind == SimpleTokenKind::LParen)
+    {
+        return CommentPlacement::Default(comment);
+    }
+
+    CommentPlacement::dangling(comment.enclosing_node(), comment)
+}
+
 /// Attach an end-of-line comment immediately following an open bracket as a dangling comment on
 /// enclosing node.
 ///