[NFC] Remove a redundant run line from concurrency test.

Author: hborla

test/Concurrency/global_actor_inference_swift6.swift

@@ -2,7 +2,6 @@
 
 // RUN: %target-swift-frontend -swift-version 6 -emit-module -emit-module-path %t/other_global_actor_inference.swiftmodule -module-name other_global_actor_inference -strict-concurrency=complete %S/Inputs/other_global_actor_inference.swift
 
-// RUN: %target-swift-frontend -swift-version 6 -I %t -disable-availability-checking %s -emit-sil -o /dev/null -verify -enable-experimental-feature GlobalActorIsolatedTypesUsability
 // RUN: %target-swift-frontend -swift-version 6 -I %t -disable-availability-checking %s -emit-sil -o /dev/null -verify -enable-experimental-feature GlobalActorIsolatedTypesUsability
 
 // REQUIRES: concurrency