Make Testhost packable except in source-only (#46480)

Author: mmitche

src/SourceBuild/patches/vstest/0001-Make-Testhost-packable-except-in-source-only.patch

@@ -0,0 +1,24 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Matt Mitchell (.NET)" <mmitche@microsoft.com>
+Date: Mon, 3 Feb 2025 10:10:50 -0800
+Subject: [PATCH] Make Testhost packable except in source-only
+
+Backport PR: https://github.com/microsoft/vstest/pull/15001
+
+---
+ .../Microsoft.TestPlatform.TestHost.csproj                      | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/package/Microsoft.TestPlatform.TestHost/Microsoft.TestPlatform.TestHost.csproj b/src/package/Microsoft.TestPlatform.TestHost/Microsoft.TestPlatform.TestHost.csproj
+index b23cfbab5..af4e6f1e5 100644
+--- a/src/package/Microsoft.TestPlatform.TestHost/Microsoft.TestPlatform.TestHost.csproj
++++ b/src/package/Microsoft.TestPlatform.TestHost/Microsoft.TestPlatform.TestHost.csproj
+@@ -5,7 +5,7 @@
+ 
+   <PropertyGroup>
+     <!-- Don't produce this package when building from source or inside the VMR as it doesn't build correctly on non-Windows. -->
+-    <IsPackable Condition="'$(DotNetBuild)' != 'true'">true</IsPackable>
++    <IsPackable Condition="'$(DotNetBuildSourceOnly)' != 'true' and '$(OS)' == 'Windows_NT'">true</IsPackable>
+     <NuspecFile>Microsoft.TestPlatform.TestHost.nuspec</NuspecFile>
+     <NuspecBasePath>$(OutputPath)</NuspecBasePath>
+     <PackageId>Microsoft.TestPlatform.TestHost</PackageId>