[heft-lint-plugin] Support for Eslint Flat Config

[Faithfinder]

All in the topic really. It will be default in v9, might as well get ahead of the train. Would be nice not to rely on the eslint-patch anymore.

[iclanton]

Does the flat config structure support pulling in rules from dependencies that use pnpm, or will it now require hoisted dependencies?

[iclanton]

Neat, looks like it does: https://eslint.org/blog/2022/08/new-config-system-part-2/#from---rulesdir-to-runtime-plugins

[Faithfinder]

https://eslint.org/blog/2023/10/flat-config-rollout-plans/

Rollout plan now available

[philsherry]

Support for ESLint flat config is only half of the problem.

It also needs to support ESLint v9 as well.

And as ESLint is up to v9.10.0 now, I’d say it’s more than stable enough.