eslint v9 support

(see also #2478, https://github.com/airbnb/javascript/issues/2223, https://github.com/airbnb/javascript/issues/2036, https://github.com/airbnb/javascript/issues/1834, https://github.com/airbnb/javascript/issues/1447)

eslint v9 was released on 2024.04.05.

The current plan is, if possible, to release a new semver-minor of both configs, that supports `7 || 8 || 9`.

Note that this is _different_ from whether flat config is supported or not by these plugins, and from whether this project will convert to flat config.

The timeframe for eslint v9 support is "not as soon as you would like, but as soon as we can".
Please accept this, and please add no noise to this thread beyond emoji reactions - distractions won't help anyone get the work done any faster.

### **Please** do not file additional issues and do not file pull requests attempting to add support - please, instead, continue to use eslint v8 until such time as our configs support v9.

Peer Dep eslint combined v7, v8, and v9 support released:
- [x] [`eslint-plugin-import`](https://github.com/import-js/eslint-plugin-import/issues/2948) ([PR](https://github.com/import-js/eslint-plugin-import/pull/2996))
- [x] flat config support ([PR](https://github.com/import-js/eslint-plugin-import/pull/3018))
- [x] [`eslint-find-rules`](https://github.com/sarbbottam/eslint-find-rules/issues/351)
- [ ] update the base config
- [ ] publish the base config, semver-minor
- [x] [`eslint-plugin-react`](https://github.com/jsx-eslint/eslint-plugin-react/issues/3699)
- [x] [flat config support](https://github.com/jsx-eslint/eslint-plugin-react/pull/3694)
- [x] [`eslint-plugin-jsx-a11y`](https://github.com/jsx-eslint/eslint-plugin-jsx-a11y/issues/978) ([PR](https://github.com/jsx-eslint/eslint-plugin-jsx-a11y/pull/1009))
- [x] [flat config support](https://github.com/jsx-eslint/eslint-plugin-jsx-a11y/pull/993)
- [x] [`eslint-plugin-react-hooks`](https://github.com/facebook/react/issues/28313)
- [x] v9 support ([PR](https://github.com/facebook/react/pull/28773))
- [x] flat config support ([PR](https://github.com/facebook/react/pull/30774))
- [ ] update the main config
- [ ] publish the main config, semver-minor

Review the checklist for the base config and main config, along with the linked dependency issues, before starting. The work is done when both configs support ESLint 7, 8, and 9 and the corresponding semver-minor releases are published; the issue asks contributors not to file implementation pull requests.

Written by the indexing model from the issue text.