Bump Xunit from 2.9.2 to 2.9.3 in /src (#587)

Author: dependabot[bot]

src/Directory.Packages.props

@@ -26,7 +26,7 @@
     <PackageVersion Include="Verify.ImageMagick" Version="3.6.0" />
     <PackageVersion Include="Verify.WinForms" Version="4.0.0" />
     <PackageVersion Include="Verify.Xunit" Version="28.8.1" />
-    <PackageVersion Include="Xunit" Version="2.9.2" />
+    <PackageVersion Include="Xunit" Version="2.9.3" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.0.0" />
     <PackageVersion Include="XunitContext" Version="3.3.2" />
   </ItemGroup>