Rollup merge of #62193 - matthewjasper:dynamic-drop-async, r=Centril

Rollup merge of #62193 - matthewjasper:dynamic-drop-async, r=Centril

Create async version of the dynamic-drop test

Some of the tests in dynamic-drop have been cut:
* The tests that are just simpler versions of other tests - these tests are already fairly slow due to all of the unwinding and async functions have more control flow paths than normal functions.
* The union test - it's for an unstable feature that has an RFC to remove it.
* The generator test - there aren't async generators yet.
* The tests that show values being leaked - these can be added once the issue is fixed.

r? @Centril
cc  #62121 @cramertj