chore(deps): update dependency ng-packagr to v21

Author: renovate[bot]

package.json

@@ -52,7 +52,7 @@
     "karma-coverage": "~2.2.1",
     "karma-jasmine": "~5.1.0",
     "karma-jasmine-html-reporter": "~2.1.0",
-    "ng-packagr": "^18.0.0",
+    "ng-packagr": "^21.0.0",
     "rxjs": "~7.8.1",
     "typescript": "~5.4.5",
     "zone.js": "~0.14.2"