build(dev-dependencies): update dependency ng-packagr to v21

Author: renovate[bot]

package.json

@@ -69,7 +69,7 @@
     "karma-coverage-istanbul-reporter": "~3.0.2",
     "karma-jasmine": "~4.0.0",
     "karma-jasmine-html-reporter": "^1.5.0",
-    "ng-packagr": "^17.0.0",
+    "ng-packagr": "^21.0.0",
     "sass": "^1.35.1",
     "ts-node": "^10.9.1",
     "tsickle": "^0.46.3",