Update name of requirements file in workflow.

Author: TeresiaOlsson

.github/workflows/deploy-pages.yml

@@ -30,7 +30,7 @@ jobs:
       - name: Install docs dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install -r requirements.txt
+          pip install -r docs-requirements.txt
 
       - name: Build Sphinx docs
         run: ./build-docs.sh