SingleGroupMatcher is chatty with wrong warning

[olamy]

Affected version

3.5.3

Bug description

When using excludedGroups to disable tagged test to run with junit5. If the build is using junit4 as well for few modules of the same project. Some noisy/wrong logs are generated such

[WARNING] Couldn't load group class 'external' in Surefire|Failsafe plugin. The group class is ignored!
[WARNING] Couldn't load group class 'large-disk-resource' in Surefire|Failsafe plugin. The group class is ignored!
[WARNING] Couldn't load group class 'stress' in Surefire|Failsafe plugin. The group class is ignored!
[WARNING] Couldn't load group class 'slow' in Surefire|Failsafe plugin. The group class is ignored!
[WARNING] Couldn't load group class 'flaky' in Surefire|Failsafe plugin. The group class is ignored!

As those values are tags used such @Tag("flaky") they should not be logged as warning. but debug only