chore: bump typescript-eslint to 8.58.2 with follow-up fixes

[suguanYang]

Summary

• bump typescript-eslint to 8.58.2
• remove the redundant test type assertions the newer lint rule now rejects
• add the required changeset file so the PR satisfies the main-bound release gate

Notes

• this is a clean human-owned follow-up PR for the Node SDK
• it covers the same tooling bump that was on Dependabot PR chore(deps-dev): bump typescript-eslint from 8.55.0 to 8.58.2 #62, but with the required follow-up fixes included
• no runtime SDK behavior is changed; this is tooling/test/release-hygiene only

Verification

• npm run format:check
• npm run lint
• npm run typecheck
• npm run test:ci
• npm run build
• npm audit --omit=dev
• npm run release:check-changeset -- origin/main