Fix pre-commit cache key in GitHub Actions. (#3740)
Fix pre-commit cache key in GitHub Actions. (#3740)

Fix pre-commit cache key to include full Python version as per
https://github.com/pre-commit/pre-commit/issues/1575#issuecomment-678792700
and https://pre-commit.com/#github-actions-example
drewja/flask,drewja/flask,pallets/flask,pallets/flask,fkazimierczak/flask,fkazimierczak/flask,pallets/flask,mitsuhiko/flask,mitsuhiko/flask,drewja/flask,fkazimierczak/flask