fix: ensure enough history is fetched in update-demo workflow to verify branch is in sync with remote during CI

Author: 56kyle

.github/workflows/update-demo.yml

@@ -19,6 +19,7 @@ jobs:
       - name: Checkout Template
         uses: actions/checkout@v4
         with:
+          fetch-depth: 0
           repository: ${{ github.repository }}
           path: "${{ github.workspace }}/cookiecutter-robust-python"