chore(deps): update dependency verify.tunit to 31.15.0

Author: renovate[bot]

src/Directory.Packages.props

@@ -27,7 +27,7 @@
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
     <PackageVersion Include="Microsoft.Reactive.Testing" Version="6.1.0" />
     <PackageVersion Include="TUnit" Version="1.22.6" />
-    <PackageVersion Include="Verify.TUnit" Version="31.13.5" />
+    <PackageVersion Include="Verify.TUnit" Version="31.15.0" />
     <PackageVersion Include="Microsoft.Testing.Extensions.CodeCoverage" Version="18.5.2" />
     <PackageVersion Include="Microsoft.Testing.Platform.MSBuild" Version="2.1.0" />
     <PackageVersion Include="PublicApiGenerator" Version="11.5.4" />