build(deps): bump coverlet.msbuild from 3.1.2 to 3.2.0 in /src

Bumps [coverlet.msbuild](https://github.com/coverlet-coverage/coverlet) from 3.1.2 to 3.2.0.
- [Release notes](https://github.com/coverlet-coverage/coverlet/releases)
- [Commits](https://github.com/coverlet-coverage/coverlet/commits/v3.2.0)

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

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

src/ReactiveUI.Validation.Tests/ReactiveUI.Validation.Tests.csproj

@@ -18,7 +18,7 @@
     <PackageReference Include="PublicApiGenerator" Version="10.3.0" />
     <PackageReference Include="xunit.runner.console" Version="2.4.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5" />
-    <PackageReference Include="coverlet.msbuild" Version="3.1.2">
+    <PackageReference Include="coverlet.msbuild" Version="3.2.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>