Bump Verify.Xunit from 20.8.0 to 25.3.1

Bumps Verify.Xunit from 20.8.0 to 25.3.1.

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

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

test/NaturalStringExtensions.Tests/NaturalStringExtensions.Tests.csproj

@@ -24,7 +24,7 @@
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
     <PackageReference Include="Xunit.SkippableFact" Version="1.4.13" />
-    <PackageReference Include="Verify.Xunit" Version="20.8.0" />
+    <PackageReference Include="Verify.Xunit" Version="25.3.1" />
     <PackageReference Include="coverlet.collector" Version="6.0.0">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>