Bump xunit.runner.visualstudio in /examples/csharp-dotnet

Bumps [xunit.runner.visualstudio](https://github.com/xunit/visualstudio.xunit) 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)

---
updated-dependencies:
- dependency-name: xunit.runner.visualstudio
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
# Conflicts:
#	examples/csharp-dotnet/tests/HelloWorld/HelloWorld.Test.csproj

Author: dependabot[bot]

examples/csharp-dotnet/tests/HelloWorld/HelloWorld.Test.csproj

@@ -13,7 +13,7 @@
         <PackageReference Include="FluentAssertions" Version="6.12.0" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
         <PackageReference Include="xunit" Version="2.7.0" />
-        <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.5.7">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
             <PrivateAssets>all</PrivateAssets>
         </PackageReference>