## Summary
Fixes#16189.
Only `sys.breakpointhook` is flagged by the upstream linter:
007a745c86/pylint/checkers/stdlib.py (L38)
but I think it makes sense to flag
[`__breakpointhook__`](https://docs.python.org/3/library/sys.html#sys.__breakpointhook__)
too, as suggested in the issue because it
> contain[s] the original value of breakpointhook [...] in case [it
happens] to get replaced with broken or alternative objects.
## Test Plan
New T100 test cases