Re-enable distributed tracing main branch

[ktoso]

Main should be good again.
Undoes #571

We require 5.2+ nowadays.

FYI @hborla @slashmo

[ktoso]

@swift-ci please test

[ktoso]

@swift-ci please test

[ktoso]

No worries, It's on us to keep it working :-)
Just FYI that we're in the compat suite with this project.

[ktoso]

@swift-ci please test

[ktoso]

The project passed, unrelated ones failing tho;

17:21:09   FAIL: Kitura, 5.1, 8578c4, Swift Package
17:21:09   FAIL: RxReactiveObjC, 5.3, ec478b, Swift Package
17:21:09   FAIL: RxReactiveObjC, 5.2, ec478b, Swift Package
17:21:09   FAIL: RxReactiveObjC, 5.1, ec478b, Swift Package
17:21:09   FAIL: RxReactiveObjC, 5.0, ec478b, Swift Package
17:21:09   FAIL: RxReactiveObjC, 4.2, ec478b, Swift Package

Resolves rdar://81907275