build(deps): bump xunit from 2.5.3 to 2.6.0 in /tests/Spice86.Tests

Bumps [xunit](https://github.com/xunit/xunit) from 2.5.3 to 2.6.0.
- [Commits](xunit/xunit@2.5.3...2.6.0)

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

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

tests/Spice86.Tests/Spice86.Tests.csproj

@@ -29,7 +29,7 @@
 	  <PrivateAssets>all</PrivateAssets>
 	  <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 	</PackageReference>
-	<PackageReference Include="xunit" Version="2.5.3" />
+	<PackageReference Include="xunit" Version="2.6.0" />
 	<PackageReference Include="xunit.runner.visualstudio" Version="2.5.3">
 	  <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 	  <PrivateAssets>all</PrivateAssets>