ci: revises pipeline to return the preview branch

Author: claymcleod

.github/workflows/deploy-preview.yml

@@ -36,7 +36,7 @@ jobs:
       id-token: write
     environment:
       name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}
+      url: ${{ steps.deployment.outputs.page_url }}/branches/${{ github.head_ref }}
     runs-on: ubuntu-latest
     steps:
       - name: Deploy to GitHub Pages