Bump the xunit group with 1 update

Bumps Verify.Xunit from 31.4.1 to 31.5.1

---
updated-dependencies:
- dependency-name: Verify.Xunit
  dependency-version: 31.5.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: xunit
...

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

Author: dependabot[bot]

Tests/Approval.Tests/Approval.Tests.csproj

@@ -14,7 +14,7 @@
     </PackageReference>
     <PackageReference Include="PublicApiGenerator" Version="11.5.0" />
     <PackageReference Include="Verify.DiffPlex" Version="3.1.2" />
-    <PackageReference Include="Verify.Xunit" Version="31.4.1" />
+    <PackageReference Include="Verify.Xunit" Version="31.5.1" />
   </ItemGroup>
 
   <ItemGroup>