[`flake8-commas`] Add support for trailing comma checks in type parameter lists (`COM812`,`COM819`) (#19390)
## Summary
Fixes #18844
I'm not too sure if the solution is as simple as the way I implemented
it, but I'm curious to see if we are covering all cases correctly here.
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Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>