Fix actions errors and warnings

.github/workflows/build-docs.yml

@@ -10,10 +10,10 @@ jobs:
   deploy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: 3.x
-      - run: pip install mkdocs[python]
+      - run: pip install mkdocs[python] mkdocstrings
       - run: mkdocs gh-deploy --force --clean --verbose