Bump xunit from 2.8.0 to 2.8.1

Bumps [xunit](https://github.com/xunit/xunit) from 2.8.0 to 2.8.1.
- [Commits](xunit/xunit@2.8.0...2.8.1)

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

Signed-off-by: dependabot[bot] <support@github.com>

tests/ImageSort.UnitTests/ImageSort.UnitTests.csproj

@@ -17,7 +17,7 @@
     </PackageReference>
     <PackageReference Include="ReactiveUI" Version="19.6.12" />
     <PackageReference Include="ReactiveUI.Testing" Version="19.6.1" />
-    <PackageReference Include="xunit" Version="2.8.0" />
+    <PackageReference Include="xunit" Version="2.8.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.7">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

tests/ImageSort.WPF.UiTests/ImageSort.WPF.UiTests.csproj

@@ -9,7 +9,7 @@
   <ItemGroup>
     <PackageReference Include="FlaUI.UIA3" Version="4.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
-    <PackageReference Include="xunit" Version="2.8.0" />
+    <PackageReference Include="xunit" Version="2.8.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.7">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>