When running multiple test products, report which ones had failures at the end

[owenv]

Currently we emit a note at the end of the log if any XCTests failed, since those run before Swift Testing tests. However, this doesn't scale to situations where we have more than one test product. With this change, we instead emit a note like:

Note: Some test targets reported failures:                                                                                                                                                      
     - TargetATests (Swift Testing)
     -  TargetBTests (XCTest)

Which will hopefully provide a better high level overview

[owenv]

@swift-ci test

[dschaefer2]

Like it. This will make it easier for advanced progress tracking we hope to do in the future.

[owenv]

@swift-ci test

[owenv]

@swift-ci test windows

[owenv]

@swift-ci test self hosted

[owenv]

@swift-ci test macOS

[owenv]

@swift-ci test windows