chore(deps): update dependency angular-eslint to v21

Author: renovate[bot]

eslint-config-angular/package.json

@@ -32,7 +32,7 @@
   "license": "MIT",
   "peerDependencies": {
     "@eslint/js": "^9.9.1",
-    "angular-eslint": "^18.1.0 || ^19.0.0 || ^20.0.0",
+    "angular-eslint": "^18.1.0 || ^19.0.0 || ^20.0.0 || ^21.0.0",
     "eslint": "^9.9.1",
     "eslint-plugin-perfectionist": "^4.6.0",
     "eslint-plugin-prefer-arrow": "^1.2.3",