Add git diff check to release workflow (#17561)

Author: desertaxle

.github/workflows/python-package.yaml

@@ -23,7 +23,6 @@ jobs:
           fetch-depth: 0
           persist-credentials: false
 
-
       - name: Set up uv and Python
         uses: astral-sh/setup-uv@v5
         with:
@@ -44,6 +43,10 @@ jobs:
         run: |
           uv run prefect dev build-ui
 
+      - name: Check git diff
+        run: |
+          git diff --exit-code
+
       - name: Build a binary wheel and a source tarball
         run: |
           uv build --sdist --wheel --out-dir dist