Avoid searching for bracketed comments in unparenthesized generators (#7627)

Similar to tuples, a generator _can_ be parenthesized or
unparenthesized. Only search for bracketed comments if it contains its
own parentheses.

Closes https://github.com/astral-sh/ruff/issues/7623.

crates/ruff_python_formatter/src/expression/expr_tuple.rs

@@ -221,7 +221,7 @@ impl NeedsParentheses for ExprTuple {
     }
 }
 
-/// Check if a tuple has already had parentheses in the input
+/// Return `true` if a tuple is parenthesized in the source code.
 pub(crate) fn is_tuple_parenthesized(tuple: &ExprTuple, source: &str) -> bool {
     let Some(elt) = tuple.elts.first() else {
         return false;