ESLint configuration compatibility with v9+

[FisherSkyi]

Tell us about your environment

• RepoSense Version: 4.0
• OS and Version: MacOS 15.6
• Web Browser and Version (if applicable):

Please include the steps to reproduce the bug.

run

npx eslint . --fix

What was expected to happen?

All eslint error autofix

What actually happened? Please include a screenshot of the output.

Oops! Something went wrong! :(

ESLint: 9.39.2

ESLint couldn't find an eslint.config.(js|mjs|cjs) file.

From ESLint v9.0.0, the default configuration file is now eslint.config.js.
If you are using a .eslintrc.* file, please follow the migration guide
to update your configuration file to the new format:

https://eslint.org/docs/latest/use/configure/migration-guide

If you still have problems after following the migration guide, please stop by
https://eslint.org/chat/help to chat with the team.

If possible, include the URL to your RepoSense report or log files (if any).

[FisherSkyi]

in frontend/package.json, we set "eslint": "^8.57.0", so this issue won't happen if we use local version of eslint via npm