Fix language multi-target issues with tests

Author: Lamparter

Directory.Build.props

@@ -11,6 +11,9 @@
 	<PropertyGroup>
 		<LangVersion>12.0</LangVersion>
 		<Nullable>enable</Nullable>
+
+		<LangMT Condition="'$(Configuration)' == 'CSharp' or '$(Configuration)' == 'VisualBasic'">$(Configuration)</LangMT>
+		<IsLangMT Condition="'$(LangMT)' != ''">true</IsLangMT>
 	</PropertyGroup>
 
 	<PropertyGroup>

eng/LanguageInternals.props

@@ -1,8 +1,8 @@
 <Project>
-	<PropertyGroup>
+	<PropertyGroup Condition="'$(IsLangMT)' == 'true'">
 		<AssemblyName>Riverside.CompilerPlatform.$(Configuration).$(MSBuildProjectName.Replace("Riverside.CompilerPlatform.", ""))</AssemblyName>
 	</PropertyGroup>
-	<ItemGroup>
+	<ItemGroup Condition="'$(IsLangMT)' == 'true'">
 		<PackageReference Include="Microsoft.CodeAnalysis.$(Configuration)" Version="4.13.0" />
 		<PackageReference Include="Microsoft.CodeAnalysis.$(Configuration).Workspaces" Version="4.13.0" />
 	</ItemGroup>