Bump @angular/cdk from 20.2.14 to 21.0.3 in /web_embedding/ng-flutter

Bumps [@angular/cdk](https://github.com/angular/components) from 20.2.14 to 21.0.3.
- [Release notes](https://github.com/angular/components/releases)
- [Changelog](https://github.com/angular/components/blob/main/CHANGELOG.md)
- [Commits](https://github.com/angular/components/compare/20.2.14...v21.0.3)

---
updated-dependencies:
- dependency-name: "@angular/cdk"
  dependency-version: 21.0.3
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

web_embedding/ng-flutter/package.json

@@ -12,7 +12,7 @@
   "private": true,
   "dependencies": {
     "@angular/animations": "^20.0.3",
-    "@angular/cdk": "^20.1.0",
+    "@angular/cdk": "^21.0.3",
     "@angular/common": "^20.1.4",
     "@angular/compiler": "^20.0.6",
     "@angular/core": "^20.0.3",