Bump coverlet.collector from 1.1.0 to 1.2.0 in /Ix.NET/Source

Bumps [coverlet.collector](https://github.com/tonerdo/coverlet) from 1.1.0 to 1.2.0.
- [Release notes](https://github.com/tonerdo/coverlet/releases)
- [Commits](coverlet-coverage/coverlet@v1.1.0...v1.2.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Ix.NET/Source/Directory.build.props

@@ -28,7 +28,7 @@
 
 
   <ItemGroup Condition="'$(IsTestProject)' == 'true'">
-    <PackageReference Include="coverlet.collector" Version="1.1.0" />
+    <PackageReference Include="coverlet.collector" Version="1.2.0" />
   </ItemGroup>