Enabled linux-musl-x64 composite images to get built. (#47104)

Author: ivdiazsa

src/Framework/App.Runtime/src/Microsoft.AspNetCore.App.Runtime.csproj

@@ -103,7 +103,7 @@ This package is an internal implementation of the .NET Core SDK and is not meant
       Special case the crossgen2 package reference on Windows to avoid the x86 package when building in Visual Studio.
     -->
     <BuildOsName>$(TargetOsName)</BuildOsName>
-    <BuildOsName Condition="'$(TargetOsName)' == 'linux-musl' and '$(TargetArchitecture)'!='x64'">linux</BuildOsName>
+    <BuildOsName Condition="'$(TargetOsName)' == 'linux-musl' and '$(TargetArchitecture)' != 'x64'">linux</BuildOsName>
     <BuildOsName Condition=" '$(PortableBuild)' == 'false' ">$(TargetRuntimeIdentifier.Substring(0,$(TargetRuntimeIdentifier.IndexOf('-'))))</BuildOsName>
     <Crossgen2BuildArchitecture Condition=" '$(BuildOsName)' == 'win' ">x64</Crossgen2BuildArchitecture>
     <Crossgen2BuildArchitecture Condition=" '$(Crossgen2BuildArchitecture)' == '' ">$(BuildArchitecture)</Crossgen2BuildArchitecture>
@@ -478,7 +478,7 @@ This package is an internal implementation of the .NET Core SDK and is not meant
   </Target>
 
   <Target Name="_GenerateComposites"
-          Condition="'$(BuildOsName)' == 'linux'"
+          Condition="'$(TargetOsName)' == 'linux' or '$(TargetOsName)' == 'linux-musl'"
           DependsOnTargets="_ExpandRuntimePackageRoot">
 
     <PropertyGroup>