build(deps): bump xunit from 2.5.0 to 2.5.1 in /src (#572)

Bumps [xunit](https://github.com/xunit/xunit) from 2.5.0 to 2.5.1.
- [Commits](xunit/xunit@2.5.0...2.5.1)

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

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

Author: dependabot[bot]

src/ReactiveUI.Validation.Tests/ReactiveUI.Validation.Tests.csproj

@@ -12,7 +12,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.2" />
-    <PackageReference Include="xunit" Version="2.5.0" />
+    <PackageReference Include="xunit" Version="2.5.1" />
     <PackageReference Include="Xunit.StaFact" Version="1.1.11" />
     <PackageReference Include="Microsoft.Reactive.Testing" Version="6.0.0" />
     <PackageReference Include="PublicApiGenerator" Version="11.0.0" />