Merge pull request #68443 from ktoso/reenable-linux-async_taskgroup_asynciterator_semantics

[Concurrency] Re-enable async_taskgroup_asynciterator_semantics on linux

Author: swift-ci

test/Concurrency/Runtime/async_taskgroup_asynciterator_semantics.swift

@@ -4,7 +4,6 @@
 // REQUIRES: concurrency
 // REQUIRES: concurrency_runtime
 // UNSUPPORTED: back_deployment_runtime
-// UNSUPPORTED: OS=linux-gnu
 
 struct Boom: Error {}