build: check for ignored files being included in repo

.forgejo/workflows/push-next.yml

@@ -30,6 +30,15 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Ignored Files
+        run: |
+          IGNORED=$(git ls-files --cached -i --exclude-standard)
+          if [ -n "$IGNORED" ]
+          then
+            echo "Ignored files present:\n$IGNORED"
+            exit 1
+          fi
+
       - name: Check TODOs
         uses: https://git.kemitix.net/kemitix/forgejo-todo-checker@v1.3.0