Bump Avalonia.Diagnostics and Avalonia

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

Updates `Avalonia.Diagnostics` from 11.0.7 to 11.0.8
- [Release notes](https://github.com/AvaloniaUI/Avalonia/releases)
- [Commits](AvaloniaUI/Avalonia@11.0.7...11.0.8)

Updates `Avalonia` from 11.0.7 to 11.0.8
- [Release notes](https://github.com/AvaloniaUI/Avalonia/releases)
- [Commits](AvaloniaUI/Avalonia@11.0.7...11.0.8)

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

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

Author: dependabot[bot]

GTiff2Tiles.Avalonia/GTiff2Tiles.Avalonia.csproj

@@ -7,9 +7,9 @@
 
     <ItemGroup>
         <!-- External dependencies -->
-        <PackageReference Include="Avalonia" Version="11.0.7" />
+        <PackageReference Include="Avalonia" Version="11.0.8" />
         <PackageReference Include="Avalonia.Desktop" Version="11.0.7" />
-        <PackageReference Include="Avalonia.Diagnostics" Version="11.0.7" />
+        <PackageReference Include="Avalonia.Diagnostics" Version="11.0.8" />
         <PackageReference Include="Avalonia.ReactiveUI" Version="11.0.7" />
         <PackageReference Include="Avalonia.Themes.Fluent" Version="11.0.7" />
         <PackageReference Include="DialogHost.Avalonia" Version="0.7.7" />