chore: update dependency @ionic/angular to ^5.9.1

Signed-off-by: Renovate Bot <bot@renovateapp.com>

Author: renovate-bot

frontend/package-lock.json

@@ -21,7 +21,7 @@
     "@angular/router": "~11.2.0",
     "@capacitor/android": "^2.4.9",
     "@capacitor/core": "2.4.9",
-    "@ionic/angular": "^5.6.10",
+    "@ionic/angular": "^5.9.1",
     "@ionic/pwa-elements": "^3.0.2",
     "@ionic/storage-angular": "^3.0.6",
     "rxjs": "~6.6.0",