Bump Verify.Xunit from 23.0.0 to 23.2.1

Bumps [Verify.Xunit](https://github.com/VerifyTests/Verify) from 23.0.0 to 23.2.1.
- [Release notes](https://github.com/VerifyTests/Verify/releases)
- [Commits](VerifyTests/Verify@23.0.0...23.2.1)

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

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

tests/Serilog.Formatting.Log4Net.Tests.csproj

@@ -16,7 +16,7 @@
     <PackageReference Include="Serilog" Version="3.1.1" />
     <PackageReference Include="Serilog.Enrichers.Environment" Version="2.3.0" />
     <PackageReference Include="Serilog.Enrichers.Thread" Version="3.1.0" />
-    <PackageReference Include="Verify.Xunit" Version="23.0.0" />
+    <PackageReference Include="Verify.Xunit" Version="23.2.1" />
     <PackageReference Include="xunit" Version="2.6.6" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6" PrivateAssets="all" />
   </ItemGroup>