chore(deps): bump @angular/core from 21.0.6 to 21.2.4 in /demo/angular

Bumps [@angular/core](https://github.com/angular/angular/tree/HEAD/packages/core) from 21.0.6 to 21.2.4.
- [Release notes](https://github.com/angular/angular/releases)
- [Changelog](https://github.com/angular/angular/blob/main/CHANGELOG.md)
- [Commits](https://github.com/angular/angular/commits/v21.2.4/packages/core)

---
updated-dependencies:
- dependency-name: "@angular/core"
  dependency-version: 21.2.4
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]