When a Jetty 12 EE 9 core (i.e., one built from the jakarta branch of jenkins) and Jetty 12 EE 9 compatible test harness (i.e., one built from the forward branch of jenkins-test-harness) are used, the following test fails:

• com.dabsquared.gitlabjenkins.webhook.build.MergeRequestBuildActionTest

This is just a trivial matter of changing the StaplerRequest/StaplerResponse imports to StaplerRequest2/StaplerResponse2. Unfortunately, this is not backward compatible with Jetty 10 or Jetty 12 EE 8, so the PR will have to remain in draft until we release Jetty 12 EE 9 support. Still, we should prepare the PR in advance.