Callable enclose in square brackets

[peco2282]

Summary

the first parameter of callable must be a parameter expression, so enclosed in square brackets.

Checklist

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• If type: ignore comments were used, a comment is also left explaining why
• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, typehinting, examples, ...)

[Dorukyum]

This doesn't seem necessary according to the examples here: https://peps.python.org/pep-0612/#concatenating-keyword-parameters

[peco2282]

This came up in my editor and I thought it was necessary.
If you don't need it, you can close it.

[Lulalaby]

This doesn't seem necessary according to the examples here: https://peps.python.org/pep-0612/#concatenating-keyword-parameters

Yeah but maybe we can consider that.

Discussion for @Pycord-Development/maintainers and @Pycord-Development/contributors
Setting on hold for now.

[VincentRPS]

I think its fine, if it makes type checkers happier.