[Test] Disabled test currently failing.

$ "T:\swift\test-windows-x86_64\Concurrency\Runtime\Output\async_taskgroup_discarding.swift.tmp/a.out"
note: command had no output on stdout or stderr
error: command failed with exit status: 3221225786

Author: nate-chandler

test/Concurrency/Runtime/async_taskgroup_discarding.swift

@@ -4,6 +4,8 @@
 // REQUIRES: executable_test
 // REQUIRES: concurrency_runtime
 
+// REQUIRES: rdar104982289
+
 // rdar://78109470
 // UNSUPPORTED: back_deployment_runtime
 
@@ -59,4 +61,4 @@ func shouldStartWith(_ lhs: Any, _ rhs: Any) {
       }
     }
   }
-}
+}