TCK tests logging "Static configuration methods can cause unexpected behavior."

[MikeEdgar]

At the start of the TCK run, we see multiple occurrences of the following warning [1]. We should consider making the @BeforeClass method non-static (for a micro release) or looking into another approach like suggested in testng-team/testng#2554 (for the next minor release).

[2024-10-15 15:15:24] [WARN   ] org.testng.log4testng.Logger warn Detected a static method [org.eclipse.microprofile.openapi.tck.AppTestBase.configureRestAssured()]. Static configuration methods can cause unexpected behavior.

[1] https://github.com/smallrye/smallrye-open-api/actions/runs/11349084528/job/31564363806?pr=2017#step:7:53