fix: update ngx-zoneless-scrollbar to version 21.0.20

Author: farshadhemmati

demo/package.json

@@ -13,7 +13,7 @@
     "@angular/core": "^19.0.0",
     "@angular/platform-browser": "^19.0.0",
     "@angular/platform-browser-dynamic": "^19.0.0",
-    "ngx-zoneless-scrollbar": "^21.0.19",
+    "ngx-zoneless-scrollbar": "^21.0.20",
     "rxjs": "^7.8.2",
     "tslib": "^2.3.0"
   },