Bump @angular/platform-server from 21.2.8 to 21.2.9

Bumps [@angular/platform-server](https://github.com/angular/angular/tree/HEAD/packages/platform-server) from 21.2.8 to 21.2.9.
- [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/v21.2.9/packages/platform-server)

---
updated-dependencies:
- dependency-name: "@angular/platform-server"
  dependency-version: 21.2.9
  dependency-type: direct:production
...

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