Enable parallel query for custom sources

Author: VictoriousRaptor

Plugins/Flow.Launcher.Plugin.Program/Programs/Win32.cs

@@ -381,6 +381,7 @@ private static string Extension(string path)
         private static IEnumerable<Win32> UnregisteredPrograms(List<ProgramSource> sources, string[] suffixes, string[] protocols)
         {
             var paths = ExceptDisabledSource(sources.Where(s => Directory.Exists(s.Location) && s.Enabled)
+                    .AsParallel()
                     .SelectMany(s => ProgramPaths(s.Location, suffixes)))
                     .Distinct();