fix(ci): use requirements.txt

Author: EvaluationContext

.github/workflows/ci.yml

@@ -18,7 +18,6 @@ jobs:
         with:
           key: ${{ github.ref }}
           path: .cache
-      - run: pip install mkdocs-material
-      - run: pip install mkdocs-meta-descriptions-plugin
+      - run: pip install -r requirements.txt
       - run: pip install pillow cairosvg
       - run: mkdocs gh-deploy --force