test: fix smoke tests

[AriPerkkio]

Continues work from #470, with fix applied from #473.

Example run: https://github.com/AriPerkkio/eslint-plugin-vitest/actions/runs/9482770552/job/26128361215

• chore: set packageManager

  • Lockfile seems to be generated with pnpm@9, but CIs are using pnpm@8
  • Contributors may end up re-generating whole lockfile if the version doesn't match with expected major

• test: fix smoke tests

  • Run tests against 10K repositories from eslint-remote-tester-repositories, instead of just a single one
  • Use required peer dependency eslint@9 - the Node API of eslint@8 is not compatible with required version 9. I wonder why there's no warning from peerDependencies conflict 🤔

[veritem]

LGTM!!!!