Fix Junit Output

[troygibb]

Seeing this failure in Jenkins:

type.3.2.2: Attribute 'successes' is not allowed to appear in element 'testsuites'.
ERROR: Step ‘Publish xUnit test result report’ failed: The result file '/home/jenkins-agent/workspace/Jdev__replay_testing__ubuntu_noble_amd64/ws/test_results/replay_testing/test_replay_tests_basic_replay.py.xunit.xml' for the metric 'JUnit' is not valid. The result file has been skipped.
Sending e-mails to: ros2-buildfarm-jazzy@googlegroups.com steven+build.ros2.org@openrobotics.org emerson@polymathrobotics.com troy@polymathrobotics.com noreply@github.com
Finished: FAILURE