build(deps): bump MessageBox.Avalonia and Avalonia in /Sample (#718)

Bumps [MessageBox.Avalonia](https://github.com/CreateLab/MessageBox.Avalonia) and [Avalonia](https://github.com/AvaloniaUI/Avalonia). These dependencies needed to be updated together.

Updates `MessageBox.Avalonia` from 1.7.1 to 3.1.5.1
- [Commits](https://github.com/CreateLab/MessageBox.Avalonia/commits)

Updates `Avalonia` from 0.10.12 to 11.0.5
- [Release notes](https://github.com/AvaloniaUI/Avalonia/releases)
- [Commits](AvaloniaUI/Avalonia@0.10.12...11.0.5)

---
updated-dependencies:
- dependency-name: MessageBox.Avalonia
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: Avalonia
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Sample/SextantSample.Avalonia/SextantSample.Avalonia.csproj

@@ -5,7 +5,7 @@
     </PropertyGroup>
     <ItemGroup>
         <PackageReference Include="Citrus.Avalonia" Version="1.6.1" />
-        <PackageReference Include="MessageBox.Avalonia" Version="1.7.1" />
+        <PackageReference Include="MessageBox.Avalonia" Version="3.1.5.1" />
     </ItemGroup>
     <ItemGroup>
         <Compile Update="**\*.xaml.cs">