Update to eslint v9, typescript-eslint v8

[jakebailey]

Blocked on:

• Update supported eslint to include v9 a-tarasyuk/eslint-formatter-autolinkable-stylish#33 (or we remove the formatter; VS Code parses ESLint's output now too sorta)
  • Worked around with an override, good enough for now.
• fix(eslint-plugin): [no-unused-vars] ignore imports used only as types typescript-eslint/typescript-eslint#9694 to be released

[jakebailey]

@webpro Do you happen to know why knip would be complaining about @typescript-eslint/rule-tester being unused, even though debug logs seem to imply that scripts/eslint/tests/support/RuleTester.cjs is analyzed?

[webpro]

@webpro Do you happen to know why knip would be complaining about @typescript-eslint/rule-tester being unused, even though debug logs seem to imply that scripts/eslint/tests/support/RuleTester.cjs is analyzed?

Not entirely sure, but some relevant bits include:

• Knip does not automatically split projects based on tsconfig.json files. This repo is a single workspace to Knip and all files are in a single ts.Program with a single custom module resolver function.
• No root tsconfig.json means no value for compilerOptions.moduleResolution when ts.resolveModuleName() is invoked. That could explain why @typescript-eslint/utils was resolved (by @import in JSDoc tag) but not @typescript-eslint/rule-tester (by require call).
• In that custom function Knip uses an additional module resolver (prior to ts.resolveModuleName). Coincidentally last week the resolve package that this is based on has been replaced with enhanced-resolve and that seems to do the trick here. Not exactly sure why, though. I expect this fix to be released this week.

[jakebailey]

Updated knip and yeah, that works, thanks!