Mark test as requiring Objective-C interoperability.

Author: tkremenek

test/APINotes/obsoleted.swift

@@ -1,6 +1,7 @@
 // RUN: not %target-swift-frontend -typecheck -verify -I %S/Inputs/custom-modules -F %S/Inputs/custom-frameworks -swift-version 3 %s
 // RUN: %target-swift-frontend -typecheck -verify -I %S/Inputs/custom-modules -F %S/Inputs/custom-frameworks -swift-version 4.2 %s
 // RUN: %target-swift-frontend -typecheck -verify -I %S/Inputs/custom-modules -F %S/Inputs/custom-frameworks -swift-version 5 %s
+// REQUIRES: objc_interop
 import ObsoletedAPINotesTest
 
 let _: FooID // expected-error{{'FooID' has been renamed to 'Foo_ID'}}