Update test_supervisor.py

[gaurimakhija]

The while loops in test_start_supervisor and other tests do not have timeouts, which may cause the tests to hang indefinitely if something goes wrong (e.g., the supervisor never starts or the API never returns the expected result).

Fix: Add a maximum retry count or timeout to prevent infinite looping:

Summary by CodeRabbit

• Bug Fixes
  • Improved the reliability of the supervisor startup tests with a new retry mechanism for container readiness.
  • Enhanced error handling to better manage timeout scenarios during container initialization.