Fix launch_ros_testing shutdown race in WaitForTopics

[mjcarroll]

• Change thread type daemon=False to follow some best practice from the pybind11 community: [BUG]: Python API calls in destructors are unsafe outside the main thread pybind/pybind11#3274
• Fix WaitForTopics context manager to appropriately clean up after itself in the case that topics aren't available
• Shutdown WaitForTopics in another test cas

[mjcarroll]

• Linux
• Linux-aarch64
• Linux-rhel
• Windows

[ahcorde]

Pulls: #511
Gist: https://gist.githubusercontent.com/ahcorde/6bd21addea18a95165b0270e7d25cf07/raw/0ebc6de570ff66c4ebb237629646c18c0abef1c3/ros2.repos
BUILD args: --packages-above-and-dependencies launch_testing_ros
TEST args: --packages-above launch_testing_ros
ROS Distro: rolling
Job: ci_launcher
ci_launcher ran: https://ci.ros2.org/job/ci_launcher/17753

• Linux
• Linux-aarch64
• Linux-rhel
• Windows

[MiguelCompany]

Apart from fixing the linter, this looks good to me.

I checked with colcon and gdb, on RelWithDebInfo and Debug, with Fast DDS 3.2.x and 3.4.x, and never got any crash or misbehavior.

[MiguelCompany]

I see something weird in the Windows CI. The output says there is only one test in launch_testing_ros, and that it has been skipped.

Starting >>> launch_testing_ros
--- output: launch_testing_ros
============================= test session starts =============================

platform win32 -- Python 3.12.3, pytest-7.4.4, pluggy-1.4.0

cachedir: C:\ci\ws\build\launch_testing_ros\.pytest_cache

rootdir: C:\ci\ws\src\ros2\launch_ros\launch_testing_ros

configfile: pytest.ini

testpaths: test

plugins: ament-copyright-0.20.3, ament-flake8-0.20.3, ament-lint-0.20.3, ament-mypy-0.20.3, ament-pep257-0.20.3, ament-xmllint-0.20.3, launch-testing-3.9.5, launch-testing-ros-0.29.4, colcon-core-0.17.1, cov-4.1.0, mock-3.12.0, repeat-0.9.3, rerunfailures-12.0, timeout-2.2.0

collected 0 items / 1 skipped



------ generated xml file: C:\ci\ws\build\launch_testing_ros\pytest.xml -------

============================= 1 skipped in 1.63s ==============================

---
Finished <<< launch_testing_ros [16.7s]

[mjcarroll]

Re-enabled the other windows test, which should be good now.

• Linux
• Linux-aarch64
• Linux-rhel
• Windows