[Files] Re-enable no-unused-vars in eslint

Bug: b:265863256
Change-Id: I86ec1b12920a2ef8b5c3745c33af3b710f82a3a1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4564894
Commit-Queue: Wenbo Jie <wenbojie@chromium.org>
Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1150157}

ui/file_manager/.eslintrc.js

@@ -14,9 +14,7 @@ module.exports = {
       '@typescript-eslint',
     ],
     'rules': {
-      // TODO(b/265863256): Re-enable when TypeScript annotations complication
-      // has been fixed.
-      '@typescript-eslint/no-unused-vars': 'off',
+      // rule override goes here.
     },
   }],
 };