use docsbuild reqs file

Co-authored-by: Hugo van Kemenade <[email protected]>

Author: AA-Turner

.github/workflows/tests.yml

@@ -19,7 +19,7 @@ jobs:
       - name: setup requirements
         run: |
           python -m pip install --upgrade pip
-          python -m pip install jinja2 markupsafe zc.lockfile requests
+          python -m pip install -r docsbuild-scripts/requirements.txt
       - name: build docs
         run: |
           python3 ./docsbuild-scripts/build_docs.py --quick --build-root ./build_root --www-root ./www --log-directory ./logs --group $(id -g) --skip-cache-invalidation --theme $(pwd) --language en --branch 3.9