[tests] Remove duplicated 'using' directives. (#18033)

tests/monotouch-test/CoreVideo/CVImageBufferTests.cs

@@ -10,7 +10,6 @@
 using System;
 using Foundation;
 using NUnit.Framework;
-using Foundation;
 using ObjCRuntime;
 using CoreVideo;
 

tests/monotouch-test/CoreVideo/CVMetalTextureCacheTests.cs

@@ -12,7 +12,6 @@
 using System;
 using Foundation;
 using NUnit.Framework;
-using Foundation;
 using ObjCRuntime;
 using CoreVideo;
 using Metal;

tests/monotouch-test/ObjCRuntime/RegistrarTest.cs

@@ -34,9 +34,6 @@ using NativeException = Foundation.MonoTouchException;
 #endif
 #endif
 using ObjCRuntime;
-#if !__TVOS__
-using MapKit;
-#endif
 #if !__WATCHOS__
 using CoreAnimation;
 #endif

tests/monotouch-test/Photos/LivePhotoEditingContextTest.cs

@@ -7,7 +7,6 @@ using CoreGraphics;
 using Foundation;
 using ObjCRuntime;
 using Photos;
-using CoreGraphics;
 using NUnit.Framework;
 
 #if !NET

tests/monotouch-test/System.Net.Http/MessageHandlers.cs

@@ -17,7 +17,6 @@ using System.Linq;
 using System.IO;
 
 using NUnit.Framework;
-using System.Net;
 using System.Net.Http.Headers;
 using System.Security.Authentication;
 using System.Text;

tests/monotouch-test/UIKit/ImageTest.cs

@@ -8,7 +8,6 @@ using System.Threading;
 using CoreGraphics;
 using Foundation;
 using UIKit;
-using CoreGraphics;
 using ObjCRuntime;
 using NUnit.Framework;
 

tests/monotouch-test/UIKit/PanGestureRecognizerTest.cs

@@ -12,8 +12,6 @@
 using System;
 using System.Drawing;
 using CoreGraphics;
-using CoreGraphics;
-using CoreGraphics;
 using Foundation;
 using UIKit;
 using NUnit.Framework;

tests/monotouch-test/VideoToolbox/VTUtilitiesTests.cs

@@ -22,7 +22,6 @@ using AppKit;
 #else
 using UIKit;
 #endif
-using CoreMedia;
 using AVFoundation;
 using CoreFoundation;
 using CoreVideo;