add a mypy workflow to check changed files only

.github/workflows/mypy.yml

@@ -0,0 +1,25 @@
+
+name: Run Lint
+
+on:
+  workflow_call:
+
+jobs:
+  static-type-check:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v3
+      with:
+        python-version: '3.10'
+    - run: pip install mypy==1.10.0
+    - name: Get Python changed files
+      id: changed-py-files
+      uses: tj-actions/[email protected]
+      with:
+        files: |
+          *.py
+          **/*.py
+    - name: Run if any of the listed files above is changed
+      if: steps.changed-py-files.outputs.any_changed == 'true'
+      run: mypy ${{ steps.changed-py-files.outputs.all_changed_files }} --ignore-missing-imports