CI: Only use approved GitHub Actions

.github/workflows/doc.yml

@@ -23,31 +23,15 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: '3.8'
-      - name: Generate requirements.txt file
-        run: |
-          cd Documentation/
-          pip3 install pipenv
-          pipenv lock -r > requirements.txt
-      - uses: ammaraskar/sphinx-problem-matcher@master
-      - uses: ammaraskar/sphinx-action@master
-        with:
-          docs-folder: "Documentation/"
-      - uses: actions/upload-artifact@v2
-        with:
-          name: sphinx-docs
-          path: Documentation/_build/html/
-  linkcheck:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v1
-      - uses: actions/setup-python@v2
-        with:
-          python-version: '3.8'
-      - uses: ammaraskar/sphinx-problem-matcher@master
-      - name: Run linkcheck
+      - name: Generate Documentation
         run: |
           cd Documentation/
           pip3 install pipenv
           pipenv install
+          pipenv run make html
           # This step flakes frequently so still annotate errors but dont fail the build
           pipenv run make linkcheck || true
+      - uses: actions/upload-artifact@v2
+        with:
+          name: sphinx-docs
+          path: Documentation/_build/html/