build: bump rust image to v3.1.0 and use check-for-ignored

.forgejo/workflows/push-next.yml

@@ -18,7 +18,7 @@ jobs:
     
     container:
       image:
-        git.kemitix.net/kemitix/rust:v3.0.0
+        git.kemitix.net/kemitix/rust:v3.1.0
     
     strategy:
       matrix:
@@ -31,13 +31,7 @@ jobs:
         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
+        run: check-for-ignored
 
       - name: Check TODOs
         uses: https://git.kemitix.net/kemitix/forgejo-todo-checker@v1.3.0