Tidy up GitHub workflows (#4191)

* Move docs build into main workflow
* Rename build.yml -> test.yml
* Rename build-mac.yml -> test_macos.yml

Author: connorjward

.github/workflows/docs.yml

@@ -296,3 +296,81 @@ jobs:
         with:
           name: zenodo-canary
           path: firedrake-install.log
+
+  build_docs:
+    name: Build documentation
+    runs-on: ubuntu-latest
+    container:
+      image: firedrakeproject/firedrake-docdeps:latest
+    outputs:
+      conclusion: ${{ steps.report.outputs.conclusion }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          path: firedrake-repo
+
+      - name: Install Firedrake
+        id: install
+        run: |
+          : # Pass '--system-site-packages' so already installed packages can be found
+          python3 -m venv --system-site-packages venv
+          . venv/bin/activate
+          pip uninstall -y firedrake
+          pip install --verbose './firedrake-repo[docs]'
+
+      - name: Check bibtex
+        run: |
+          . venv/bin/activate
+          make -C firedrake-repo/docs validate-bibtex
+
+      - name: Check documentation links
+        run: |
+          . venv/bin/activate
+          make -C firedrake-repo/docs linkcheck
+
+      - name: Build docs
+        id: build
+        if: success() || steps.install.conclusion == 'success'
+        run: |
+          . venv/bin/activate
+          cd firedrake-repo/docs
+          make html
+          make latex
+          make latexpdf
+
+      - name: Copy manual to HTML tree
+        id: copy
+        if: success() || steps.build.conclusion == 'success'
+        run: |
+          cd firedrake-repo/docs
+          cp build/latex/Firedrake.pdf build/html/_static/manual.pdf
+
+      - name: Upload artifact
+        id: upload
+        if: success() || steps.copy.conclusion == 'success'
+        uses: actions/upload-pages-artifact@v3
+        with:
+          name: github-pages
+          path: /__w/firedrake/firedrake/firedrake-repo/docs/build/html
+          retention-days: 1
+
+      - name: Report status
+        id: report
+        if: success() || steps.upload.conclusion == 'success'
+        run: echo "conclusion=success" >> "$GITHUB_OUTPUT"
+
+  deploy:
+    name: Deploy Github pages
+    needs: build_docs
+    # Always run this workflow on master, even if linkcheck fails
+    if: always() && github.ref == 'refs/heads/master' && needs.build_docs.outputs.conclusion == 'success'
+    permissions:
+      pages: write
+      id-token: write
+    environment:
+      name: github-pages
+      url: http://firedrakeproject.github.io/firedrake
+    runs-on: ubuntu-latest
+    steps:
+      - name: Deploy to GitHub Pages
+        uses: actions/deploy-pages@v4