👷 Add pre-commit GitHub Action workflow (#4895)

Co-authored-by: pre-commit <[email protected]>

.github/workflows/autoformat.yml

@@ -0,0 +1,43 @@
+name: Auto Format
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+
+jobs:
+  autoformat:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        ref: ${{ github.head_ref }}
+    - name: Set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.10'
+    - uses: actions/cache@v2
+      id: cache
+      with:
+        path: ${{ env.pythonLocation }}
+        key: ${{ runner.os }}-python-${{ env.pythonLocation }}-${{ hashFiles('pyproject.toml') }}-v01
+    - name: Install Flit
+      if: steps.cache.outputs.cache-hit != 'true'
+      run: pip install flit
+    - name: Install Dependencies
+      if: steps.cache.outputs.cache-hit != 'true'
+      run: flit install --symlink
+    - uses: actions/cache@v2
+      id: pre-commit-hooks-cache
+      with:
+        path: ~/.cache/pre-commit
+        key: ${{ runner.os }}-pre-commit-hooks-${{ hashFiles('.pre-commit-config.yaml') }}-v01
+    - name: Run pre-commit
+      run: pre-commit run --all-files
+    - name: Commit pre-commit changes
+      if: failure()
+      run: |
+        git config --global user.name "pre-commit"
+        git config --global user.email [email protected]
+        git add --update
+        git commit -m "🎨 Format code with pre-commit"
+        git push