Remove 'NETSDK1219' warning

Author: Sergio0694

src/Tasks/Common/Resources/Strings.resx

@@ -957,10 +957,7 @@ You may need to build the project on another operating system or architecture, o
     <value>NETSDK1218: This project has a transitive dependency on the full Windows SDK projections (including Windows.UI.Xaml.* types), but does not specify the UseUwp property. That must be enabled to ensure that .NET types are projected and marshalled correctly for interop scenarios with these XAML types.</value>
     <comment>{StrBegin="NETSDK1218: "}</comment>
   </data>
-  <data name="UsingPreviewUseUwpFeature" xml:space="preserve">
-    <value>NETSDK1219: UseUwp and all associated functionality are currently experimental and not officially supported.</value>
-    <comment>{StrBegin="NETSDK1219: "}</comment>
-  </data>
+  <!-- Skipping NETSDK1219 on purpose, as that is "UsingPreviewUseUwpFeature" on .NET < 9.0.2xx, and has been removed on new SDK versions -->
   <data name="WindowsSDKXamlInvalidTfm" xml:space="preserve">
     <value>NETSDK1220: UseUwp and all associated functionality require using a TFM of 'net8.0-windows' or greater.</value>
     <comment>{StrBegin="NETSDK1220: "}</comment>

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Windows.targets

@@ -167,16 +167,4 @@ Copyright (c) .NET Foundation. All rights reserved.
                       and '$(UseUwp)' == 'true' ">
     <NetSdkError ResourceName="WindowsSDKXamlInvalidTfm" />
   </Target>
-
-  <!--
-    Emit a warning if 'UseUwp' is set.
-
-    NOTE: remove this target when 'UseUwp' becomes officially supported.
-  -->
-  <Target Name="_WarnForUseUwpPreviewFeatureEnabled"
-          AfterTargets="ResolvePackageAssets"
-          Condition=" '$(IncludeWindowsSDKRefFrameworkReferences)' == 'true'
-                      and '$(UseUwp)' == 'true'">
-    <NETSdkWarning ResourceName="UsingPreviewUseUwpFeature" />
-  </Target>
 </Project>

test/Microsoft.NET.Build.Tests/GivenThatWeWantToBuildAWindowsDesktopProject.cs

@@ -453,8 +453,9 @@ public void ItUsesTheHighestMatchingWindowsSdkPackageVersion(string targetFramew
 
         }
 
+        // We used to emit NETSDK1219 while UWP support on .NET 9 was not GA yet, make sure it's gone now
         [WindowsOnlyFact]
-        public void ItWarnsWhenBuildingAProjectWithUseUwpProperty()
+        public void ItDoesNotWarnAnymoreWhenBuildingAProjectWithUseUwpProperty()
         {
             TestProject testProject = new()
             {
@@ -472,7 +473,7 @@ public void ItWarnsWhenBuildingAProjectWithUseUwpProperty()
                 .Should()
                 .Pass()
                 .And
-                .HaveStdOutContaining("NETSDK1219");
+                .NotHaveStdOutContaining("NETSDK1219");
         }
 
         [WindowsOnlyFact]