Code Quality: Run update checks in background task

Update-related service calls are now executed concurrently in a background Task to avoid blocking the main thread and improve application responsiveness during startup.

Author: yaira2

src/Files.App/Helpers/Application/AppLifecycleHelper.cs

@@ -157,9 +157,14 @@ public static async Task CheckAppUpdate()
 				ViewedReleaseNotes = true;
 			}
 
-			await updateService.CheckForUpdatesAsync();
-			await updateService.DownloadMandatoryUpdatesAsync();
-			await updateService.CheckAndUpdateFilesLauncherAsync();
+			_ = Task.Run(async () =>
+			{
+				await Task.WhenAll(
+					updateService.CheckForUpdatesAsync(),
+					updateService.DownloadMandatoryUpdatesAsync(),
+					updateService.CheckAndUpdateFilesLauncherAsync(),
+				);
+			});
 		}
 
 		/// <summary>