Bump Verify.Xunit from 28.12.0 to 28.13.0 in the testing group

Bumps the testing group with 1 update: [Verify.Xunit](https://github.com/VerifyTests/Verify).


Updates `Verify.Xunit` from 28.12.0 to 28.13.0
- [Release notes](https://github.com/VerifyTests/Verify/releases)
- [Commits](VerifyTests/Verify@28.12.0...28.13.0)

---
updated-dependencies:
- dependency-name: Verify.Xunit
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: testing
...

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

Author: dependabot[bot]

test/Tests.csproj

@@ -22,7 +22,7 @@
     </PackageReference>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.13.0" />
     <PackageReference Include="Shouldly" Version="4.3.0" />
-    <PackageReference Include="Verify.Xunit" Version="28.12.0" />
+    <PackageReference Include="Verify.Xunit" Version="28.13.0" />
     <PackageReference Include="xunit" Version="2.9.3" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.0.2">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>