updated decompression support (#26)

- update decompression functions to use native libs
- add support for 7zip and tar.xz archives with SharpCompress
- add .7z and tar.xz artifacts to releases
- remove linux non-appimage builds from PRs

Reviewed-on: https://git.ryujinx.app/projects/Ryubing/pulls/26

src/Ryujinx/Systems/Updater/Updater.GitLab.cs

@@ -91,7 +91,7 @@ namespace Ryujinx.Ava.Systems
             }
 
             // If build URL not found, assume no new update is available.
-            if (_versionResponse.ArtifactUrl is null or "")
+            if (string.IsNullOrEmpty(_versionResponse.ArtifactUrl))
             {
                 if (showVersionUpToDate)
                 {
@@ -123,6 +123,8 @@ namespace Ryujinx.Ava.Systems
                 return default;
             }
 
+            _connectionCount = (int)_versionResponse.MaxConcurrency;
+
             return (currentVersion, newVersion);
         }
     }