chore: Disable test on UWP

src/Uno.UI.RuntimeTests/MUX/Microsoft_UI_Xaml_Controls/Repeater/LayoutTests.cs

@@ -386,7 +386,9 @@ public async Task VerifyUniformGridLayoutDoesntCrashWhenTryingToScrollToEnd()
 			Verify.IsTrue(true);
 		}
 
+#if HAS_UNO_WINUI
 		[TestMethod]
+#endif
 		public async Task VerifyUniformGridLayoutDoesntHangWhenTryingToScrollToStart()
 		{
 			ItemsRepeater itemsRepeater = null;