build(deps): bump xunit from 2.5.1 to 2.6.1 in /src (#3667)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/Directory.build.props

@@ -45,7 +45,7 @@
 
   <ItemGroup Condition="$(IsTestProject)">
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.2" />
-    <PackageReference Include="xunit" Version="2.5.1" />
+    <PackageReference Include="xunit" Version="2.6.1" />
     <PackageReference Include="xunit.runner.console" Version="2.5.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.3" />
     <PackageReference Include="Xunit.StaFact" Version="1.1.11" />