Enable dispatch queue on Apple platforms (#329)

Author: xiazhvera

Package.swift

@@ -151,11 +151,11 @@ awsCIoPlatformExcludes.append("source/windows")
 awsCIoPlatformExcludes.append("source/linux")
 awsCIoPlatformExcludes.append("source/s2n")
 cSettingsIO.append(.define("__APPLE__"))
-cSettingsIO.append(.define("AWS_ENABLE_DISPATCH_QUEUE", .when(platforms: [.iOS, .tvOS, .macOS])))
+cSettingsIO.append(.define("AWS_ENABLE_DISPATCH_QUEUE"))
 cSettingsIO.append(.define("AWS_USE_SECITEM", .when(platforms: [.iOS, .tvOS])))
 cSettingsIO.append(.define("AWS_ENABLE_KQUEUE", .when(platforms: [.macOS])))
 swiftTestSettings.append(.define("__APPLE__"))
-swiftTestSettings.append(.define("AWS_ENABLE_DISPATCH_QUEUE", .when(platforms: [.iOS, .tvOS, .macOS])))
+swiftTestSettings.append(.define("AWS_ENABLE_DISPATCH_QUEUE"))
 swiftTestSettings.append(.define("AWS_USE_SECITEM", .when(platforms: [.iOS, .tvOS])))
 swiftTestSettings.append(.define("AWS_ENABLE_KQUEUE", .when(platforms: [.macOS])))
 #endif