build(deps): bump xunit from 2.5.1 to 2.6.1 in /src (#753)

Bumps [xunit](https://github.com/xunit/xunit) from 2.5.1 to 2.6.1.
- [Commits](xunit/xunit@2.5.1...2.6.1)

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

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

src/DynamicData.Tests/DynamicData.Tests.csproj

@@ -12,7 +12,7 @@
 
   <ItemGroup>
     <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="2.6.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.3" />
     <PackageReference Include="FluentAssertions" Version="6.12.0" />