Fail if formatters have made changes

Author: Preocts

.github/workflows/python-tests.yml

@@ -100,3 +100,9 @@ jobs:
 
       - name: "Run linters and formatters"
         run: "uvx nox --session format lint"
+
+      - name: "Check for any unstaged changes"
+        run: |
+          if [ 0 -ne $(git status --porcelain) ]; then
+            exit 1
+          fi