Update SourceLink to 2.1.0

Rx.NET/Source/Directory.build.props

@@ -24,12 +24,12 @@
   
   <ItemGroup>
     <PackageReference Include="GitVersionTask" Version="4.0.0-beta0011" PrivateAssets="All" /> 
-    <PackageReference Include="MSBuild.Sdk.Extras" Version="1.0.0" PrivateAssets="All" />
+    <PackageReference Include="MSBuild.Sdk.Extras" Version="1.0.2" PrivateAssets="All" />
   </ItemGroup>
   
   <ItemGroup Condition="'$(IsTestProject)' != 'true'">
-    <PackageReference Include="SourceLink.Create.GitHub" Version="2.0.2" PrivateAssets="All" /> 
-    <DotNetCliToolReference Include="dotnet-sourcelink-git" Version="2.0.2" />
+    <PackageReference Include="SourceLink.Create.GitHub" Version="2.1.0" PrivateAssets="All" /> 
+    <DotNetCliToolReference Include="dotnet-sourcelink-git" Version="2.1.0" />
   </ItemGroup>
   
   <!-- Workaround -->
@@ -48,4 +48,4 @@
       BeforeTargets="_GenerateRestoreProjectSpec"
       DependsOnTargets="GetVersion"
       Condition=" '$(GitVersion_Task_targets_Imported)' == 'True' " />
-</Project>
+</Project>