Bump Verify.Xunit from 20.5.0 to 20.5.1 in /src (#371)

src/DiffEngineTray.Tests/DiffEngineTray.Tests.csproj

@@ -10,7 +10,7 @@
     <PackageReference Include="Argon" Version="0.7.2" />
     <PackageReference Include="Verify.DiffPlex" Version="2.2.1" />
     <PackageReference Include="Verify.WinForms" Version="4.0.0" />
-    <PackageReference Include="Verify.Xunit" Version="20.5.0" />
+    <PackageReference Include="Verify.Xunit" Version="20.5.1" />
     <PackageReference Include="Verify.ImageMagick" Version="3.2.2" />
     <PackageReference Include="Xunit" Version="2.5.0" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.0" PrivateAssets="all" />