[Concurrency] backdeploy library has no taskGroup_initializeWithFlags (swiftlang#63006)

Author: ktoso

stdlib/public/BackDeployConcurrency/CompatibilityOverrideConcurrency.def

@@ -241,10 +241,6 @@ OVERRIDE_TASK_GROUP(taskGroup_initialize, void,
                     SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
                     swift::, (TaskGroup *group, const Metadata *T), (group, T))
 
-OVERRIDE_TASK_GROUP(taskGroup_initializeWithFlags, void,
-                    SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
-                    swift::, (size_t flags, TaskGroup *group, const Metadata *T), (flags, group, T))
-
 OVERRIDE_TASK_STATUS(taskGroup_attachChild, void,
                     SWIFT_EXPORT_FROM(swift_Concurrency), SWIFT_CC(swift),
                     swift::, (TaskGroup *group, AsyncTask *child),