fix: Upgrade eslint to v10 to resolve @eslint/plugin-kit ReDoS vulnerability (#11705)
## Summary
Fixes TURBO-5239. Upgrades `eslint` from `9.26.0` to `10.0.0` in
`eslint-config-turbo` and `eslint-plugin-turbo` to resolve a ReDoS
vulnerability in `@eslint/plugin-kit@0.2.8` (requires `>=0.3.4`).
`eslint@10.0.0` depends on `@eslint/plugin-kit@^0.6.0`, which resolves
to `0.6.0`.
## Changes
- Bumped `eslint` devDependency to `10.0.0` in both packages
- Added `@eslint/core` as a devDependency (required by eslint 10's type
re-exports for declaration emit)
- Removed deprecated `category` property from rule metadata
(`RulesMetaDocs` no longer has it in eslint 10)
- Migrated `Linter.FlatConfig` to `Linter.Config` (flat config is now
the default/only format)
- Added explicit type annotations to `plugin`, `rules`, and `configs`
exports to fix TS2742 declaration emit errors
## Verification
- `pnpm why @eslint/plugin-kit -r` confirms `0.6.0` (above the `>=0.3.4`
fix threshold)
- Both `eslint-plugin-turbo` and `eslint-config-turbo` build
successfully
- No deprecated eslint context APIs were in use (already using modern
`context.filename`, `context.cwd`, etc.)