Update dependency Verify.Xunit to 30.15.0

Author: renovate[bot]

Directory.Packages.props

@@ -21,7 +21,7 @@
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.4" />
     <PackageVersion Include="Nullable" Version="1.3.1" />
     <PackageVersion Include="System.Reactive" Version="6.0.0" />
-    <PackageVersion Include="Verify.Xunit" Version="30.13.0" />
+    <PackageVersion Include="Verify.Xunit" Version="30.15.0" />
     <PackageVersion Include="xunit" Version="2.9.3" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2">
       <PrivateAssets>all</PrivateAssets>