Rename ruff ruleset: `TCH` → `TC` (#10373)

Ruff 0.8.0 changes the error codes for the rules in the flake8-type-checking
category from TCH to TC. This matches changes that were made in the original
flake8-type-checking plugin from which these rules were originally adapted.

https://astral.sh/blog/ruff-v0.8.0#new-error-codes-for-flake8-type-checking-rules