Bump xunit from 2.7.0 to 2.8.0 (#250)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: MihailsKuzmins <47413092+MihailsKuzmins@users.noreply.github.com>

tests/MudBlazor.Markdown.Tests/MudBlazor.Markdown.Tests.csproj

@@ -13,7 +13,7 @@
 		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
 		<PackageReference Include="MoqMicrosoftConfiguration" Version="1.0.5" />
 		<PackageReference Include="MyNihongo.Option" Version="2.2.0" />
-		<PackageReference Include="xunit" Version="2.7.0" />
+		<PackageReference Include="xunit" Version="2.8.0" />
 		<PackageReference Include="xunit.runner.visualstudio" Version="2.8.0">
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 			<PrivateAssets>all</PrivateAssets>