Bump the dev-dependencies group in /tests with 4 updates

Bumps the dev-dependencies group in /tests with 4 updates: [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest), [xunit](https://github.com/xunit/xunit), [xunit.runner.visualstudio](https://github.com/xunit/visualstudio.xunit) and [coverlet.collector](https://github.com/coverlet-coverage/coverlet).


Updates `Microsoft.NET.Test.Sdk` from 17.7.2 to 17.9.0
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Changelog](https://github.com/microsoft/vstest/blob/main/docs/releases.md)
- [Commits](microsoft/vstest@v17.7.2...v17.9.0)

Updates `xunit` from 2.5.1 to 2.7.0
- [Commits](xunit/xunit@2.5.1...2.7.0)

Updates `xunit.runner.visualstudio` from 2.5.6 to 2.5.7
- [Release notes](https://github.com/xunit/visualstudio.xunit/releases)
- [Commits](xunit/visualstudio.xunit@2.5.6...2.5.7)

Updates `coverlet.collector` from 6.0.0 to 6.0.2
- [Release notes](https://github.com/coverlet-coverage/coverlet/releases)
- [Commits](coverlet-coverage/coverlet@v6.0.0...v6.0.2)

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: dev-dependencies
- dependency-name: xunit
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: dev-dependencies
- dependency-name: xunit.runner.visualstudio
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dev-dependencies
- dependency-name: coverlet.collector
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dev-dependencies
...

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

tests/RiimutTest.csproj

@@ -7,13 +7,13 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.2" />
-    <PackageReference Include="xunit" Version="2.5.1" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
+    <PackageReference Include="xunit" Version="2.7.0" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.7">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="coverlet.collector" Version="6.0.0">
+    <PackageReference Include="coverlet.collector" Version="6.0.2">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>