chore(deps): update dependency verify.xunit to v29

Author: renovate[bot]

src/Splat.DependencyInjection.SourceGenerator.Tests/Splat.DependencyInjection.SourceGenerator.Tests.csproj

@@ -14,7 +14,7 @@
     <PackageReference Include="coverlet.msbuild" Version="6.0.2" />
     <PackageReference Include="Verify.SourceGenerators" Version="2.4.3" />
     <PackageReference Include="ReactiveMarbles.SourceGenerator.TestNuGetHelper" Version="1.3.1" />
-    <PackageReference Include="Verify.Xunit" Version="26.6.0" />
+    <PackageReference Include="Verify.Xunit" Version="29.4.0" />
     <PackageRefernece Include="Microsoft.CodeAnalysis.CSharp" Version="4.0.1" PrivateAssets="all" />
   </ItemGroup>