Migrate remaining tests to JUnit 5 where possible

[wilkinsona]

[HaydenMeloche]

Hey @wilkinsona, I might be able to tackle this. Is their anything specific to this besides removing all junit4 references and replacing them with their junit5 counterparts?

[philwebb]

@HaydenMeloche Unfortunately there's a few things blocking us from migrating entirely. We have a few JUnit 4 specific classes that we need to replace before we can really continue. I think @wilkinsona was planning to look ModifiedClassPathRunner first.

[wilkinsona]

I was indeed. I made a start yesterday, in fact. I've assigned this issue to me now. Sorry for the confusion.

[sbrannen]

Edit: comment moved to #16957.

[wilkinsona]

Closed by b18fffa.