Bump the dependencies group with 3 updates

Bumps the dependencies group with 3 updates: [xunit](https://github.com/xunit/xunit), [xunit.runner.visualstudio](https://github.com/xunit/visualstudio.xunit) and [Markdig](https://github.com/xoofx/markdig).


Updates `xunit` from 2.7.0 to 2.7.1
- [Commits](xunit/xunit@2.7.0...2.7.1)

Updates `xunit.runner.visualstudio` from 2.5.7 to 2.5.8
- [Release notes](https://github.com/xunit/visualstudio.xunit/releases)
- [Commits](xunit/visualstudio.xunit@2.5.7...2.5.8)

Updates `Markdig` from 0.36.2 to 0.37.0
- [Release notes](https://github.com/xoofx/markdig/releases)
- [Changelog](https://github.com/xoofx/markdig/blob/master/changelog.md)
- [Commits](xoofx/markdig@0.36.2...0.37.0)

---
updated-dependencies:
- dependency-name: xunit
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dependencies
- dependency-name: xunit.runner.visualstudio
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dependencies
- dependency-name: Markdig
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: dependencies
...

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

WinQuickLook.Core.Tests/WinQuickLook.Core.Tests.csproj

@@ -18,8 +18,8 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
     <PackageReference Include="Moq" Version="4.20.70" />
-    <PackageReference Include="xunit" Version="2.7.0" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.7">
+    <PackageReference Include="xunit" Version="2.7.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.8">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>

WinQuickLook.Core/WinQuickLook.Core.csproj

@@ -8,7 +8,7 @@
   <ItemGroup>
     <PackageReference Include="AvalonEdit" Version="6.3.0.90" />
     <PackageReference Include="Cylinder.WPF" Version="1.0.0-preview.2" />
-    <PackageReference Include="Markdig" Version="0.36.2" />
+    <PackageReference Include="Markdig" Version="0.37.0" />
     <PackageReference Include="Microsoft.Web.WebView2" Version="1.0.2420.47" />
   </ItemGroup>