chore(deps): Bump xunit from 2.4.1 to 2.9.3

---
updated-dependencies:
- dependency-name: xunit
  dependency-version: 2.9.3
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

csharp/Link.Foundation.Links.Notation.Tests/Link.Foundation.Links.Notation.Tests.csproj

@@ -15,7 +15,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
-    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="xunit" Version="2.9.3" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" PrivateAssets="All" />
     <PackageReference Include="coverlet.collector" Version="3.1.2" PrivateAssets="All" />
   </ItemGroup>