multi-line exception with duplicate BaseException and comments gives invalid code

[jakkdl]

before

try:
    ...
except (
    BaseException,
    BaseException # b
):
    ...

after

try:
    ...
except (BaseException, BaseException # b):
    ...

info

• flags: none (and any I tried seemed to make no difference)
• version: 3.15.0
• real-life code (although it's an intentionally "bad" test file): https://github.com/Zac-HD/flake8-trio/blob/main/tests/eval_files/trio103.py#L195

I expect you never intend to output invalid code, and similar errors could probably pop up in normal usage. I don't have much of an opinion on whether pyupgrade does nothing, or actually manages to remove the BaseException and move the comment somewhere else.