Bump upload-artifacts to v4

Author: robtaylor

.github/workflows/deploy-site.yml

@@ -83,7 +83,7 @@ jobs:
         uses: actions/configure-pages@v5
 
       - name: Upload artifacts
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: html-docs
           path: docs/_build
@@ -113,4 +113,4 @@ jobs:
           number: ${{ github.event.number }}
           id: deploy-preview
           message: "A preview of ${{ github.event.after }} is uploaded and can be seen here:\n\n ✨ ${{ env.BASE_URL }} ✨\n\nChanges may take a few minutes to propagate. Since this is a preview of production, content with `draft: true` will not be rendered. The source is here: https://github.com/${{ github.repository }}/tree/gh-pages/${{ env.PR_PATH }}/"
-          recreate: true
+          recreate: true