:man_farmer: `test_communication` -> `test_subscriber_terminates_in_a_finite_amount_of_time` and `test_processes_finished_gracefully` failing on Windows

Bug report

Required Info:

• Operating System:
  • Windows
• Installation type:
  • Source
• Version or commit hash:
  • main
• DDS implementation:
  • Fast-RTPS
• Client library (if applicable):
  • rclpy

Steps to reproduce issue

Check nightly windows jobs on the buildfarm.
Reference job showing an error in jenkins with both test_subscriber_terminates_in_a_finite_amount_of_time and test_processes_finished_gracefully failing.
https://ci.ros2.org/view/nightly/job/nightly_win_deb/2284/

Expected behavior

All test pass.

Actual behavior

These error appear constantly in the logs. It's flaky in the sense that the affected templated test differ from run to run, but most of the time at least one occur. However, important information, not all the times the error is shown in the jenkins report, for example, in the reference case attached above the following errors are shown in the UI:

projectroot.test_publisher_subscriber__rclpy__rmw_fastrtps_cpp
test_communication.TestPublisherSubscriber.test_subscriber_terminates_in_a_finite_amount_of_time[UnboundedSequences]
test_communication.TestPublisherSubscriberAfterShutdown.test_processes_finished_gracefully[UnboundedSequences]
test_communication.TestPublisherSubscriber.test_subscriber_terminates_in_a_finite_amount_of_time[WStrings]
test_communication.TestPublisherSubscriberAfterShutdown.test_processes_finished_gracefully[WStrings]

However, if you run grep on the log file looking for "FAIL: " you'll see the following list:

142: FAIL: test_subscriber_terminates_in_a_finite_amount_of_time[BoundedSequences] (test_communication.TestPublisherSubscriber)
142: FAIL: test_processes_finished_gracefully[BoundedSequences] (test_communication.TestPublisherSubscriberAfterShutdown)
143: FAIL: test_processes_finished_gracefully[Empty] (test_communication.TestRequesterReplierAfterShutdown)
142: FAIL: test_processes_finished_gracefully[Arrays] (test_communication.TestPublisherSubscriberAfterShutdown)
142: FAIL: test_subscriber_terminates_in_a_finite_amount_of_time[Empty] (test_communication.TestPublisherSubscriber)
142: FAIL: test_processes_finished_gracefully[Empty] (test_communication.TestPublisherSubscriberAfterShutdown)
142: FAIL: test_subscriber_terminates_in_a_finite_amount_of_time[Nested] (test_communication.TestPublisherSubscriber)
142: FAIL: test_processes_finished_gracefully[Nested] (test_communication.TestPublisherSubscriberAfterShutdown)
142: FAIL: test_processes_finished_gracefully[Strings] (test_communication.TestPublisherSubscriberAfterShutdown)
142: FAIL: test_processes_finished_gracefully[UnboundedSequences] (test_communication.TestPublisherSubscriberAfterShutdown)
142: FAIL: test_subscriber_terminates_in_a_finite_amount_of_time[WStrings] (test_communication.TestPublisherSubscriber)
142: FAIL: test_processes_finished_gracefully[WStrings] (test_communication.TestPublisherSubscriberAfterShutdown)
142: FAIL: test_subscriber_terminates_in_a_finite_amount_of_time[UnboundedSequences] (test_communication.TestPublisherSubscriber)
142: FAIL: test_processes_finished_gracefully[UnboundedSequences] (test_communication.TestPublisherSubscriberAfterShutdown)
142: FAIL: test_subscriber_terminates_in_a_finite_amount_of_time[WStrings] (test_communication.TestPublisherSubscriber)
142: FAIL: test_processes_finished_gracefully[WStrings] (test_communication.TestPublisherSubscriberAfterShutdown)

More info:
Templated tests: https://github.com/ros2/system_tests/blob/master/test_communication/test/test_publisher_subscriber.cpp
Actual test failures (problems related to finishing the process cleanly on windows):
https://github.com/ros2/system_tests/blob/44ac714f2cd201b2a2c98949595e953d5a289191/test_communication/test/test_publisher_subscriber.py.in#L67
and https://github.com/ros2/system_tests/blob/44ac714f2cd201b2a2c98949595e953d5a289191/test_communication/test/test_publisher_subscriber.py.in#L75

Start with test_communication/test/test_publisher_subscriber.cpp and the generated test_communication/test/test_publisher_subscriber.py.in around lines 67 and 75. Reproduce the failures in the nightly Windows job and compare the Jenkins UI with the full log, including the rclpy Fast-RTPS cases. Done means the affected communication and shutdown tests finish cleanly on Windows.