chore: update http import lock data

[SyMind]

Summary

Commit the buildHttp lockfile cache (http-import.lock.data/) for the rspack/http-import example instead of gitignoring it.

Rspack's experiments.buildHttp (aligned with webpack) defaults frozen to true in production mode: a build with a lockfile entry but no matching content in the lockfile cache fails with:

ERROR in ./src/index.js 1:1-55
  × https://www.unpkg.com/the-answer is missing content in the lockfile cache, but lockfile is frozen

This broke the examples suite in rstack-ecosystem-ci, which runs rspack build (production mode by default) in this example with only http-import.lock committed.

Changes:

• Delete rspack/http-import/.gitignore so the cache directory is tracked.
• Commit the cached content for https://www.unpkg.com/the-answer under http-import.lock.data/.
• Refresh valid_until in http-import.lock to match the regenerated cache.

Related links

• Failing ecosystem CI run: https://github.com/rstackjs/rstack-ecosystem-ci/actions/runs/34826921522/job/103921202678
• Related Rspack change enforcing frozen lockfile integrity: fix: enforce HttpUriPlugin lockfile integrity in frozen builds web-infra-dev/rspack#15609