[Bug]: Testing library waits extra time before completing test

[anthonyting]

Expected Behavior

The testing library test exits immediately when the execution finishes.

Actual Behavior

Every execution that runs in the testing library waits an additional 100ms for the test to drain its checkpoint queue. This is due to a hack where we wait an extra 100ms before exiting the run function.

See: https://github.com/aws/aws-durable-execution-sdk-js/blob/main/packages/aws-durable-execution-sdk-js-testing/src/test-runner/local/test-execution-orchestrator.ts#L166-L171

Steps to Reproduce

1. Run an execution and log the time at the end
2. The promise will resolve 100ms after the end of the execution

SDK Version

1.1.0

Node.js Version

22.x

Is this a regression?

No

Last Working Version

No response

Additional Context

No response