Remove pre-commit from CI, using pre-commit.ci instead

.github/workflows/ci.yaml

@@ -51,20 +51,3 @@ jobs:
               with:
                   name: ${{ matrix.arch }}
                   path: dist
-
-    # TODO: switch to pre-commit.ci
-    pre-commit:
-        runs-on: ubuntu-20.04
-        steps:
-            - uses: actions/checkout@v2
-
-            - name: Set up Python
-              uses: actions/setup-python@v2
-              with:
-                  python-version: '3.8'
-
-            - name: Install tox
-              run: pip install tox
-
-            - name: Run pre-commit
-              run: tox -e pre-commit