Use junit-bom instead of single JUnit 5 versions

I have noticed from 95e8e95e that the Surefire project declares JUnit dependency versions separately. That commit upgraded the junit-jupiter dependencies to 5.9.3 and the junit-platform dependency to 1.9.2. However, I assume the latter should have been 1.9.3 to stay in line with the junit-jupiter version.

If keeping the junit-platform version behind is not on purpose, I propose to use instead the junit-bom which would coordinate versioning of all the related JUnit modules.