Remove pre-commit GHA workflow (pydata#6120)

Author: andersy005

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,6 +2,5 @@
 
 - [ ] Closes #xxxx
 - [ ] Tests added
-- [ ] Passes `pre-commit run --all-files`
 - [ ] User visible changes (including notable bug fixes) are documented in `whats-new.rst`
 - [ ] New functions/methods are listed in `api.rst`