build(deps): bump coverlet.msbuild from 3.2.0 to 6.0.0 (#176)

Bumps [coverlet.msbuild](https://github.com/coverlet-coverage/coverlet) from 3.2.0 to 6.0.0.
- [Release notes](https://github.com/coverlet-coverage/coverlet/releases)
- [Commits](coverlet-coverage/coverlet@v3.2.0...v6.0.0)

---
updated-dependencies:
- dependency-name: coverlet.msbuild
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/Splat.DependencyInjection.SourceGenerator.Tests/Splat.DependencyInjection.SourceGenerator.Tests.csproj

@@ -11,7 +11,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.3" />
     <PackageReference Include="xunit" Version="2.4.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5" PrivateAssets="all" />
-    <PackageReference Include="coverlet.msbuild" Version="3.2.0" />
+    <PackageReference Include="coverlet.msbuild" Version="6.0.0" />
     <PackageReference Include="Verify.SourceGenerators" Version="1.5.0" />
     <PackageReference Include="ReactiveMarbles.SourceGenerator.TestNuGetHelper" Version="1.2.21" />
     <PackageReference Include="Verify.Xunit" Version="19.12.0" />