Remove unnecessary references

src/Features/LanguageServer/Protocol/Microsoft.CodeAnalysis.LanguageServer.Protocol.csproj

@@ -30,9 +30,6 @@
     <PackageReference Include="Microsoft.VisualStudio.Text.UI" Version="$(MicrosoftVisualStudioTextUIVersion)" />
     <PackageReference Include="Microsoft.VisualStudio.Threading" Version="$(MicrosoftVisualStudioThreadingVersion)" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFramework)' == 'net472'">
-    <Reference Include="System.ComponentModel.Composition" />
-  </ItemGroup>
 
   <ItemGroup>
     <InternalsVisibleTo Include="Microsoft.CodeAnalysis.LanguageServer.Protocol.UnitTests" />

src/Workspaces/Remote/ServiceHub/Microsoft.CodeAnalysis.Remote.ServiceHub.csproj

@@ -38,11 +38,6 @@
     <PackageReference Include="Microsoft.VisualStudio.Threading" Version="$(MicrosoftVisualStudioThreadingVersion)" />
     <PackageReference Include="Microsoft.ServiceHub.Framework" Version="$(MicrosoftServiceHubFrameworkVersion)" />
   </ItemGroup>
-  <ItemGroup Condition="'$(TargetFramework)' == 'net472'">
-    <Reference Include="System" />
-    <Reference Include="System.ComponentModel.Composition" />
-    <Reference Include="System.Core" />
-  </ItemGroup>
   <ItemGroup>
     <PublicAPI Include="PublicAPI.Shipped.txt" />
     <PublicAPI Include="PublicAPI.Unshipped.txt" />