fix(timers): prevent duplicate timer creation

utils/TimerMgr.js

@@ -10,6 +10,10 @@ class TimerMgr {
     }
 
     create(id, timeout, func) {
+        if (this.hasTimer(id)) {
+            log.error(`Timer with id ${id} already exists`);
+            return;
+        }
         log.debug("Create timer with id " + id);
         this.#timers[id] = actions.ScriptExecution.createTimer(id, timeout, func);
     }