Merge pull request #1181 from dotnet/dependabot/nuget/Rx.NET/Source/coverlet.collector-1.2.1

Rx.NET/Source/Directory.build.props

@@ -33,7 +33,7 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(IsTestProject)' == 'true'">
-    <PackageReference Include="coverlet.collector" Version="1.2.0" />
+    <PackageReference Include="coverlet.collector" Version="1.2.1" />
   </ItemGroup>
 
 </Project>