Enable the import/no-cycle ESLint plugin rule

Having cyclical imports is obviously not a good idea, and this ESLint plugin rule can help detect those; please see https://github.com/import-js/eslint-plugin-import/blob/main/docs/rules/no-cycle.md

src/scripting_api/event.js

@@ -13,9 +13,10 @@
  * limitations under the License.
  */
 
-import { USERACTIVATION_CALLBACKID } from "./app.js";
-
-const USERACTIVATION_MAXTIME_VALIDITY = 5000;
+import {
+  USERACTIVATION_CALLBACKID,
+  USERACTIVATION_MAXTIME_VALIDITY,
+} from "./app_utils.js";
 
 class Event {
   constructor(data) {