test: Validate lockfiles without dependency downloads (#12789)
## Summary
- Avoids full dependency installs in lockfile pruning checks while
preserving package-manager validation of pruned lockfiles.
- Uses no-download validation paths for npm, pnpm, Yarn Classic, Yarn
Berry, and Bun.
## Testing
- `pnpm --package=oxfmt@0.34.0 dlx oxfmt --check
lockfile-tests/check-lockfiles.ts lockfile-tests/runners/local.ts
lockfile-tests/types.ts`
- `pnpm --package=tsx@4.21.0 dlx tsx lockfile-tests/check-lockfiles.ts
--fixture does-not-exist`
- Exercised validation probes for npm, pnpm 7/8/10, Yarn Classic, Yarn
Berry, plus stale-lockfile negative probes.
- Pre-push hook ran format, TOML format check, and Rust checks
successfully.