Install missing stubs in pipeline

Author: Jufik

.github/workflows/test.yml

@@ -56,7 +56,9 @@ jobs:
         if: steps.cache.outputs.cache-hit != 'true'
         run: python -m poetry install
       - name: Lint
-        run: python -m poetry run bash scripts/lint.sh
+        run: |
+          mypy --install-types
+          python -m poetry run bash scripts/lint.sh
       - run: mkdir coverage
       - name: Test
         run: python -m poetry run bash scripts/test.sh