Prevent negative Retry-After headers

[robgruen]

This pull request introduces enhancements to the way retry delays are handled and tested in the codebase, specifically focusing on simulating and verifying retry logic for API calls. The main changes include improvements to the test suite for retry behavior and better simulation of asynchronous delays.

Testing improvements:

• Added a new test to simulate and verify the retry-after delay mechanism in the API call logic, including mocking setTimeout to track scheduled delays and ensure correct behavior after retries.

Retry logic enhancements:

• Improved handling of retry delays by capturing and asserting the correct delay values when a retry is triggered, ensuring that the logic for retrying after a failure is robust and testable.