only check for go mod files updates

.github/workflows/ci.yml

@@ -44,7 +44,13 @@ jobs:
 
       - name: Check Go tidiness
         run: |
-          nix develop --command go-tidy-all && git diff-files --name-only && git diff-files --quiet
+          nix develop --command go-tidy-all 
+          changed_files=$(git diff-files --name-only | grep -cv ".toml$")
+          if [[ $changed_gomods != 0 ]]; then
+            echo "Go modules are not so tidy (run `go-tidy-all` to fix it):"
+            git diff-files --name-only
+            exit 1
+          fi
 
   build_publish_images:
     name: Test, build and publish images