Bump @angular/language-service in /src/Web/WebSPA/Client

Bumps [@angular/language-service](https://github.com/angular/angular/tree/HEAD/packages/language-service) from 19.2.15 to 21.0.0.
- [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/21.0.0/packages/language-service)

---
updated-dependencies:
- dependency-name: "@angular/language-service"
  dependency-version: 21.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

src/Web/WebSPA/Client/package.json

@@ -53,7 +53,7 @@
     "@angular-devkit/build-angular": "20.3.11",
     "@angular/cli": "20.3.11",
     "@angular/compiler-cli": "20.3.13",
-    "@angular/language-service": "20.3.13",
+    "@angular/language-service": "21.0.0",
     "@types/jasmine": "5.1.8",
     "@types/node": "22.15.30",
     "eslint": "9.28.0",