Include deprecation/warning failures in JUnit logs

[mondrake]

When test are configured to fail in case of deprecations/warnings etc, failing tests correctly cause the testrunner to error, and deprecation/warning infromation is reported in the STDOUT (if runner is configured so), but the failures are not included in the JUnit log.

This effectively means in integrated CI environments that the test are reported as failing, but no information about the failure on the CI job, unless you look into raw logs.

Drupal completed support of PHPUnit 10 in https://www.drupal.org/project/drupal/issues/3417066, and this is visible on GitLabCI pipelines when tests trigger deprecations or warnings.

It would be good to have a flag to enable including all failures in the JUnit log.