Transport test to verify that the transport can be restarted fails on the build server

[andreasohlund]

Describe the suggested improvement

Is your improvement related to a problem? Please describe.

The When_started_again transport test works fine locally but the sent message isn't received within the allotted time on the build agent

Describe the suggested solution

Find a way to re-enable the test

Additional Context

No response

[WilliamBZA]

This also affects the following tests:

• When_multiple_messages_are_available_and_concurrency_is_increased_after_pump_started
• When_multiple_messages_are_available_and_concurrency_is_increased_and_decreased_after_pump_st
• When_multiple_messages_are_available_and_concurrency_is_lowered_after_pump_started

After some investigation it seems to be connected to message visibility timeouts, but the task force that found these flaky tests wasn't able to fix it within the time we had.