eslint-config/eslint-plugin: Support "Flat Config" (ESLint 9)

Description

👋 Coming over from https://github.com/eslint/eslint/issues/18093: ESLint is migrating to a new "flat config" format that will be the default in ESLint v9.

It doesn't look like @react-native-community/eslint-plugin has support yet. I'm posting this issue here as a reference & cross-linking it to the table in https://github.com/eslint/eslint/issues/18093. If there's anything technical blocking the extension from supporting flat configs, please let us know - we'd be happy to try to help! 💜

Additional resources:

• Configuration Migration Guide
• (edit) Plugin Migration Guide
• Blog posts on the new config system: Part 1: Background, Part 2: Introduction to flat config

(sorry for not using the issue template properly - I wasn't sure how best to report this)

Steps to reproduce

1. Have an eslint.config.js (flat config)
2. See setup instructions https://www.npmjs.com/package/@react-native-community/eslint-plugin
3. Note the missing mention of flat config

React Native Version

n/a

Affected Platforms

Other (please specify)

Output of npx react-native info

n/a

Stacktrace or Logs

n/a

Reproducer

n/a

Screenshots and Videos

No response