ci: improve lint-pr-title action (#1692)

## Summary
- Move `commitlint.config.mjs` into `.github/actions/lint-pr-title/` —
it's action-specific, not repo-wide
- Add `.npmrc` with `omit-lockfile-registry-resolved=true` to strip
internal registry URLs from the lock file
- Commit `package-lock.json` for reproducible, cacheable installs and
switch to `npm ci`
- Add `reopened` to workflow trigger types so validation runs when a
closed PR is reopened
- Simplify ESM imports and pass `parserOpts` from `load()` into `lint()`

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
* Pull request title checks now also run when a pull request is
reopened.
* Commit title validation now consistently applies the configured commit
rules and linting/parsing options.
* **Chores**
* Improved automated check setup by using a clean install method for the
title linting action.
* Prevented install scripts from running and reduced lockfile registry
metadata noise.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: yogeshchoudhary147

.github/actions/lint-pr-title/.npmrc

@@ -0,0 +1,2 @@
+ignore-scripts=true
+omit-lockfile-registry-resolved=true