Try building docs alternatively

.github/workflows/documentation.yaml

@@ -18,17 +18,21 @@ jobs:
         with:
           miniforge-variant: Mambaforge
           channels: "conda-forge, pytorch"
-          python-version: ${{ matrix.python-version }}
+          python-version: "3.9"
           auto-update-conda: true
           use-mamba: true
           auto-activate-base: true
-          activate-environment: ""
+          activate-environment: "myenv"
       - name: Install dependencies
         run: |
-          mamba install -c conda-forge -n base -y openff-amber-ff-ports openff-forcefields openff-interchange openff-interchange-base openff-models openff-toolkit openff-toolkit-base openff-units openff-utilities openmm openmmforcefields && pip install -e . && pip install -r docs/.docs.requirements
+          mamba create -n myenv -y openff-amber-ff-ports openff-forcefields openff-interchange openff-interchange-base openff-models openff-toolkit openff-toolkit-base openff-units openff-utilities openmm openmmforcefields
+          source activate myenv
+          pip install -e .
+          pip install -r docs/.docs.requirements
       - name: Sphinx build
         run: |
-          . /root/mambaforge/etc/profile.d/conda.sh && conda activate base && rm -rf docs/build/ && sphinx-build docs/source/ docs/build/
+          source activate myenv
+          rm -rf docs/build/ && sphinx-build docs/source/ docs/build/
       - name: Deploy to GitHub Pages
         uses: peaceiris/actions-gh-pages@v4
         if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}