Treat comments on open parentheses in return annotations as dangling (#6413)

## Summary

Given:

```python
def double(a: int) -> ( # Hello
    int
):
    return 2*a
```

We currently treat `# Hello` as a trailing comment on the parameters
(`(a: int)`). This PR adds a placement method to instead treat it as a
dangling comment on the function definition itself, so that it gets
formatted at the end of the definition, like:

```python
def double(a: int) -> int:  # Hello
    return 2*a
```

The formatting in this case is unchanged, but it's incorrect IMO for
that to be a trailing comment on the parameters, and that placement
leads to an instability after changing the grouping in #6410.

Fixing this led to a _different_ instability related to tuple return
type annotations, like:

```python
def zrevrangebylex(self, name: _Key, max: _Value, min: _Value, start: int | None = None, num: int | None = None) -> (  # type: ignore[override]
):
    ...
```

(This is a real example.)

To fix, I had to special-case tuples in that spot, though I'm not
certain that's correct.

crates/ruff_python_formatter/tests/snapshots/format@statement__function.py.snap

@@ -377,6 +377,44 @@ def f(  # first
     # third
 ):
     ...
+
+# Handle comments on empty tuple return types.
+def zrevrangebylex(self, name: _Key, max: _Value, min: _Value, start: int | None = None, num: int | None = None) -> (  # type: ignore[override]
+): ...
+
+def zrevrangebylex(self, name: _Key, max: _Value, min: _Value, start: int | None = None, num: int | None = None) -> (  # type: ignore[override]
+    # comment
+): ...
+
+def zrevrangebylex(self, name: _Key, max: _Value, min: _Value, start: int | None = None, num: int | None = None) -> (  # type: ignore[override]
+    1
+): ...
+
+def zrevrangebylex(self, name: _Key, max: _Value, min: _Value, start: int | None = None, num: int | None = None) -> (  # type: ignore[override]
+    1, 2
+): ...
+
+def zrevrangebylex(self, name: _Key, max: _Value, min: _Value, start: int | None = None, num: int | None = None) -> (  # type: ignore[override]
+    (1, 2)
+): ...
+
+def handleMatch(  # type: ignore[override] # https://github.com/python/mypy/issues/10197
+    self, m: Match[str], data: str
+) -> Union[Tuple[None, None, None], Tuple[Element, int, int]]:
+    ...
+
+def double(a: int # Hello
+) -> (int):
+    return 2 * a
+
+def double(a: int) -> ( # Hello
+    int
+):
+    return 2*a
+
+def double(a: int) -> ( # Hello
+):
+    return 2*a
 ```
 
 ## Output
@@ -905,6 +943,89 @@ def f(  # first
     /,  # second
 ):
     ...
+
+
+# Handle comments on empty tuple return types.
+def zrevrangebylex(
+    self,
+    name: _Key,
+    max: _Value,
+    min: _Value,
+    start: int | None = None,
+    num: int | None = None,
+) -> (  # type: ignore[override]
+):
+    ...
+
+
+def zrevrangebylex(
+    self,
+    name: _Key,
+    max: _Value,
+    min: _Value,
+    start: int | None = None,
+    num: int | None = None,
+) -> (  # type: ignore[override]
+    # comment
+):
+    ...
+
+
+def zrevrangebylex(
+    self,
+    name: _Key,
+    max: _Value,
+    min: _Value,
+    start: int | None = None,
+    num: int | None = None,
+) -> 1:  # type: ignore[override]
+    ...
+
+
+def zrevrangebylex(
+    self,
+    name: _Key,
+    max: _Value,
+    min: _Value,
+    start: int | None = None,
+    num: int | None = None,
+) -> (  # type: ignore[override]
+    1,
+    2,
+):
+    ...
+
+
+def zrevrangebylex(
+    self,
+    name: _Key,
+    max: _Value,
+    min: _Value,
+    start: int | None = None,
+    num: int | None = None,
+) -> (1, 2):  # type: ignore[override]
+    ...
+
+
+def handleMatch(  # type: ignore[override] # https://github.com/python/mypy/issues/10197
+    self, m: Match[str], data: str
+) -> Union[Tuple[None, None, None], Tuple[Element, int, int]]:
+    ...
+
+
+def double(
+    a: int,  # Hello
+) -> int:
+    return 2 * a
+
+
+def double(a: int) -> int:  # Hello
+    return 2 * a
+
+
+def double(a: int) -> (  # Hello
+):
+    return 2 * a
 ```