fix lint workflow

> Note: You should not use path filtering to skip workflow runs ipf the
workflow has been configured to be required. For more information, see
"Required workflows."

reference: https://docs.github.com/en/actions/using-workflows/triggering-a-workflow#example-including-paths

.github/workflows/lint.yml

@@ -2,8 +2,8 @@ name: Linting
 
 on:
   pull_request:
-    paths:
-      - "**/*.rb"
+    branches:
+      - main
 
 permissions:
   contents: read