test: fix for activities in tick objects prune function

PR-URL: nodejs#26163
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/async-hooks/verify-graph.js

@@ -23,12 +23,15 @@ function pruneTickObjects(activities) {
     data: null
   };
 
+  if (!Array.isArray(activities))
+    return activities;
+
   while (tickObject.found) {
     for (let i = 0; i < activities.length; i++) {
       if (activities[i].type === 'TickObject') {
         tickObject.index = i;
         break;
-      } else if (i + 1 === activities.length) {
+      } else if (i + 1 >= activities.length) {
         tickObject.found = false;
       }
     }