docs(bigframes): Resume deployment to GitHub Pages (googleapis#16974)

Tested manually at
https://github.com/tswast/google-cloud-python/actions/runs/25460952016
and http://tswast.github.io/google-cloud-python/

Fixes #<issue_number_goes_here> 🦕

Author: tswast

.github/workflows/bigframes-docs-deploy.yaml

@@ -0,0 +1,65 @@
+name: Deploy BigFrames docs to GitHub Pages
+
+on:
+  # Runs on pushes targeting the default branch
+  push:
+    branches: ["main"]
+    paths:
+      - "packages/bigframes/docs/**"
+      - ".github/workflows/bigframes-docs-deploy.yaml"
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+# Allow only one concurrent deployment, skipping runs queued between the run in-progress and latest queued.
+# However, do NOT cancel in-progress runs as we want to allow these production deployments to complete.
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  # Build job
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v6
+      # Use a fetch-depth of 2 to avoid error `fatal: origin/main...HEAD: no merge base`
+      # See https://github.com/googleapis/google-cloud-python/issues/12013
+      # and https://github.com/actions/checkout#checkout-head.
+      with:
+        fetch-depth: 2
+    - name: Setup Python
+      uses: actions/setup-python@v6
+      with:
+        python-version: "3.10"
+    - name: Install nox
+      run: |
+        python -m pip install --upgrade setuptools pip wheel
+        python -m pip install nox
+    - name: Run docs
+      working-directory: ./packages/bigframes
+      run: |
+        nox -s docs
+    - name: Upload artifact
+      uses: actions/upload-pages-artifact@v5
+      with:
+        path: packages/bigframes/docs/_build/html/
+
+  # Deployment job
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v5