Remove obsolete Assets alias path from eslint config

Remove the old './spec/dummy/client/app/assets' alias that no longer exists
after monorepo restructuring. Keep only the valid path pointing to
'./react_on_rails/spec/dummy/client/app/assets'.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

eslint.config.ts

@@ -90,7 +90,6 @@ const config = tsEslint.config([
 
       'import/resolver': {
         alias: [
-          ['Assets', './spec/dummy/client/app/assets'],
           ['Assets', './react_on_rails/spec/dummy/client/app/assets'],
         ],