Change upload-pages-artifact version

Author: r-ford

.github/workflows/deploy.yml

@@ -38,7 +38,7 @@ jobs:
       - name: Build HTML Assets
         run: myst build --html
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v4
+        uses: actions/upload-pages-artifact@v3
         with:
           path: './_build/html'
       - name: Deploy to GitHub Pages