chore(deps): bump @angular/ssr from 20.3.7 to 20.3.21

Bumps [@angular/ssr](https://github.com/angular/angular-cli) from 20.3.7 to 20.3.21.
- [Release notes](https://github.com/angular/angular-cli/releases)
- [Changelog](https://github.com/angular/angular-cli/blob/main/CHANGELOG.md)
- [Commits](angular/angular-cli@20.3.7...v20.3.21)

---
updated-dependencies:
- dependency-name: "@angular/ssr"
  dependency-version: 20.3.21
  dependency-type: direct:production
...

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

Author: dependabot[bot]

examples/angular/package.json

@@ -32,7 +32,7 @@
     "@angular/platform-browser-dynamic": "^20.2.2",
     "@angular/platform-server": "^20.2.2",
     "@angular/router": "^20.2.2",
-    "@angular/ssr": "^20.2.2",
+    "@angular/ssr": "^20.3.21",
     "@firebase-oss/ui-angular": "workspace:*",
     "@firebase-oss/ui-core": "workspace:*",
     "@firebase-oss/ui-styles": "workspace:*",