Bump tar and @angular/cli in /samples/spa-client

Bumps [tar](https://github.com/isaacs/node-tar) to 7.5.5 and updates ancestor dependency [@angular/cli](https://github.com/angular/angular-cli). These dependencies need to be updated together.


Updates `tar` from 6.2.1 to 7.5.5
- [Release notes](https://github.com/isaacs/node-tar/releases)
- [Changelog](https://github.com/isaacs/node-tar/blob/main/CHANGELOG.md)
- [Commits](https://github.com/isaacs/node-tar/compare/v6.2.1...v7.5.5)

Updates `@angular/cli` from 18.2.11 to 21.1.0
- [Release notes](https://github.com/angular/angular-cli/releases)
- [Changelog](https://github.com/angular/angular-cli/blob/main/CHANGELOG.md)
- [Commits](https://github.com/angular/angular-cli/compare/18.2.11...v21.1.0)

---
updated-dependencies:
- dependency-name: tar
  dependency-version: 7.5.5
  dependency-type: indirect
- dependency-name: "@angular/cli"
  dependency-version: 21.1.0
  dependency-type: direct:development
...

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

samples/spa-client/package.json

@@ -24,7 +24,7 @@
   },
   "devDependencies": {
     "@angular-devkit/build-angular": "^18.2.11",
-    "@angular/cli": "^18.2.11",
+    "@angular/cli": "^21.1.0",
     "@angular/compiler-cli": "^18.2.0",
     "@types/jasmine": "~5.1.0",
     "jasmine-core": "~5.2.0",