Update dependency Verify.Xunit to 26.4.0 (#42)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

src/Directory.Packages.props

@@ -14,7 +14,7 @@
     <PackageVersion Include="Microsoft.Reactive.Testing" Version="6.0.1" />
     <PackageVersion Include="PublicApiGenerator" Version="11.1.0" />
     <PackageVersion Include="coverlet.msbuild" Version="6.0.2" />
-    <PackageVersion Include="Verify.Xunit" Version="26.3.1" />
+    <PackageVersion Include="Verify.Xunit" Version="26.4.0" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
     <PackageVersion Include="Nerdbank.GitVersioning" Version="3.6.143" />
     <PackageVersion Include="stylecop.analyzers" Version="1.2.0-beta.556" />