chore: remove update button from main toolbar

Remove the 'Check for Updates' button from the main window toolbar.
Updates are available via Preferences → Updates, which is sufficient.

Sources/Views/MainView.swift

@@ -12,7 +12,6 @@ struct MainView: View {
     private static let serverOrderKeyStatic = "serverOrder"
     private static let storedServersKeyStatic = "storedServers"
 
-    @EnvironmentObject private var sparkleUpdater: SparkleUpdater
     @State var showAddServerSheet: Bool = false
     @State private var serverBeingEdited: Server?
     @State private var serverToDelete: Server?
@@ -60,14 +59,6 @@ struct MainView: View {
                     }
                     .help("Add Host")
                 }
-                ToolbarItem {
-                    Button {
-                        sparkleUpdater.checkForUpdates()
-                    } label: {
-                        Image(systemName: "square.and.arrow.down")
-                    }
-                    .help("Check for Updates")
-                }
             }
             .navigationTitle("Servers")
             .onChange(of: selectedServerID) {