Try to fix pre-commit + black + GitHub Action again

.github/workflows/pre-commit.yml

@@ -13,8 +13,4 @@ jobs:
     - uses: actions/setup-python@v2
     - name: set PY
       run: echo "::set-env name=PY::$(python -c 'import hashlib, sys;print(hashlib.sha256(sys.version.encode()+sys.executable.encode()).hexdigest())')"
-    - uses: actions/cache@v1
-      with:
-        path: ~/.cache/pre-commit
-        key: pre-commit|${{ env.PY }}|${{ hashFiles('.pre-commit-config.yaml') }}
     - uses: pre-commit/action@v2.0.0