scripting: close the VM's window when updating its configuration

A VM's window is kept after it stops and run(vm:) reuses it as is. The Edit
button closes it before opening the settings, but AppleScript's update
configuration did not. If the displays were removed that way, the next start
got the old display window, which looks up the now missing display 0 and
crashes with an index out of range.

Close the window before updating the configuration, like the Edit button does,
so the next start creates the right kind of window.

Resolves #7882

Assisted-by: Claude:claude-opus-5-5

Scripting/UTMScriptingConfigImpl.swift

@@ -34,6 +34,7 @@ import Foundation
             guard vm.state == .stopped else {
                 throw ScriptingError.notStopped
             }
+            data.close(vm: box) // close window
             let wrapper = UTMScriptingConfigImpl(vm.config)
             try wrapper.updateConfiguration(from: newConfiguration)
             try await data.save(vm: box)