[Bug]: failed tests due to unexpected PENDING status

[zhongkechen]

Expected Behavior

Test cases should always succeed

Actual Behavior

Occasional test failures due to unexpected PENDINGs

e.g. https://github.com/aws/aws-durable-execution-sdk-java/actions/runs/25229191191/job/73980791164

Error:  software.amazon.lambda.durable.examples.CloudBasedIntegrationTest.testCallbackExample -- Time elapsed: 6.826 s <<< ERROR!
java.lang.IllegalStateException: Execution succeeded while invocation failed with: Cannot return PENDING status with no pending operations.
	at software.amazon.lambda.durable.testing.TestResult.getStatus(TestResult.java:60)
	at software.amazon.lambda.durable.examples.CloudBasedIntegrationTest.testCallbackExample(CloudBasedIntegrationTest.java:399)

another occurrence:

https://github.com/aws/aws-durable-execution-sdk-java/actions/runs/25487263783/job/74785960080?pr=377

Error:  Tests run: 34, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 388.4 s <<< FAILURE! -- in software.amazon.lambda.durable.examples.CloudBasedIntegrationTest
Error:  software.amazon.lambda.durable.examples.CloudBasedIntegrationTest.testComplexFlatMapExample -- Time elapsed: 7.490 s <<< ERROR!
java.lang.IllegalStateException: Execution succeeded while invocation failed with: Cannot return PENDING status with no pending operations.
	at software.amazon.lambda.durable.testing.TestResult.getStatus(TestResult.java:60)
	at software.amazon.lambda.durable.examples.CloudBasedIntegrationTest.testComplexFlatMapExample(CloudBasedIntegrationTest.java:699)

Steps to Reproduce

Run the case CloudBasedIntegrationTest.testCallbackExample or CloudBasedIntegrationTest.testComplexFlatMapExample multiple times

SDK Version

1.0.1

Java Version

17

Is this a regression?

No

Last Working Version

No response

Additional Context

No response