Adjust ESLint rule for file names

.eslintrc

@@ -23,7 +23,7 @@
     }
   },
   "rules": {
-    "filenames/match-regex": [2, "^[a-z0-9_]+(.js)?$"],
+    "filenames/match-regex": [2, "^[a-z0-9_]+$"],
     "no-multiple-empty-lines": ["error", { "max": 1 }]
   }
 }

changelogs/unreleased/remove-es6-extension.yml

+---
+title: Remove es6 file extension from JavaScript files
+merge_request: 9241
+author: winniehell