chore(deps): update dependency xunit to 2.9.1

Author: renovate[bot]

HAProxy.StreamProcessingOffload.AgentFramework.Tests/HAProxy.StreamProcessingOffload.AgentFramework.Tests.csproj

@@ -9,7 +9,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
     <PackageReference Include="Moq" Version="4.20.70" />
-    <PackageReference Include="xunit" Version="2.9.0" />
+    <PackageReference Include="xunit" Version="2.9.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <internalAssets>all</internalAssets>