Bump ngxtension from 4.0.0 to 4.2.1 in /client

Bumps [ngxtension](https://github.com/ngxtension/ngxtension-platform) from 4.0.0 to 4.2.1.
- [Release notes](https://github.com/ngxtension/ngxtension-platform/releases)
- [Changelog](https://github.com/ngxtension/ngxtension-platform/blob/main/CHANGELOG.md)
- [Commits](ngxtension/ngxtension-platform@4.0.0...4.2.1)

---
updated-dependencies:
- dependency-name: ngxtension
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>