Add prerelease jobs (backport #459)

[mergify]

Can be activated by

• workflow dispatch manual action
• adding labels: check-prerelease or check-prerelease-downstream. Once one of the label is added, it will be triggered by subsequent updates of the PR.

If not activated, github lists them as "skipped". Nothing I can do against it afaik.

---

This is an automatic backport of pull request #459 done by Mergify.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 59.11%. Comparing base (9d9064e) to head (ace280d).

Additional details and impacted files

@@           Coverage Diff           @@
##           humble     #460   +/-   ##
=======================================
  Coverage   59.11%   59.11%           
=======================================
  Files          28       28           
  Lines        1541     1541           
  Branches      839      839           
=======================================
  Hits          911      911           
  Misses        243      243           
  Partials      387      387           

Flag	Coverage Δ
unittests	59.11% <ø> (ø)

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[christophfroehlich]

2025-09-03T10:16:45.8428041Z test 1
2025-09-03T10:16:45.8428318Z     Start 1: copyright
2025-09-03T10:16:45.8428544Z 
2025-09-03T10:16:45.8431056Z 1: Test command: /usr/bin/python3 "-u" "/opt/ros/humble/share/ament_cmake_test/cmake/run_test.py" "/tmp/ws2/test_results/gazebo_ros2_control/copyright.xunit.xml" "--package-name" "gazebo_ros2_control" "--output-file" "/tmp/ws2/build_isolated/gazebo_ros2_control/ament_copyright/copyright.txt" "--command" "/opt/ros/humble/bin/ament_copyright" "--xunit-file" "/tmp/ws2/test_results/gazebo_ros2_control/copyright.xunit.xml"
2025-09-03T10:16:45.8433714Z 1: Test timeout computed to be: 200
2025-09-03T10:16:45.8434352Z 1: -- run_test.py: invoking following command in '/tmp/ws2/src/gazebo_ros2_control':
2025-09-03T10:16:45.8435632Z 1:  - /opt/ros/humble/bin/ament_copyright --xunit-file /tmp/ws2/test_results/gazebo_ros2_control/copyright.xunit.xml
2025-09-03T10:16:45.8436523Z 1: CONTRIBUTING.md: file not found
2025-09-03T10:16:45.8436945Z 1: LICENSE: file not found
2025-09-03T10:16:45.8437304Z 1: 2 errors, checked 7 files
2025-09-03T10:16:45.8437704Z 1: -- run_test.py: return code 1
2025-09-03T10:16:45.8438418Z 1: -- run_test.py: verify result file '/tmp/ws2/test_results/gazebo_ros2_control/copyright.xunit.xml'
2025-09-03T10:16:45.8439418Z 1/6 Test #1: copyright ........................***Failed    0.24 sec