The tests use xUnit 2, which is not actively developed compared to xUnit 3 (which is also what Aspire uses).

This will require moving to MTP, probably MTP 2.0 (no point starting at 1.0 as it's already been revved), so does result in an overhaul of the way tests are run in our CI pipeline.

We will be blocked due to Tyrrrz/GitHubActionsTestLogger#41 and I don't want to drop that logger from CI, but there's an active PR Tyrrrz/GitHubActionsTestLogger#53