Use waitForInternalEnqueue helper in dedupe test

Replace the ad-hoc runBlocking { delay(100) } in the new
LoginUserOperation dedupe test with the same waitForInternalEnqueue
helper every other test in the file uses. Deterministic instead of
a fixed 100ms race against CI.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: nan-li

OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/operations/OperationRepoTests.kt

@@ -161,9 +161,7 @@ class OperationRepoTests : FunSpec({
 
         // When — enqueue the incoming op (simulates enqueueLogin landing after recovery)
         operationRepo.enqueue(incomingOp)
-
-        // Yield so the launched coroutine in enqueue() can run
-        kotlinx.coroutines.runBlocking { delay(100) }
+        mocks.waitForInternalEnqueue()
 
         // Then — queue has only the original op, with merged existingOnesignalId
         operationRepo.queue.size shouldBe 1