Update for Flutter 3.10 beta (#1746)

## Pre-launch Checklist

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [ ] All existing and new tests are passing.

---------

Co-authored-by: David Iglesias <ditman@gmail.com>
Co-authored-by: Mark Thompson <2554588+MarkTechson@users.noreply.github.com>
Co-authored-by: John Ryan <ryjohn@google.com>

simplistic_calculator/macos/Runner/MainFlutterWindow.swift

@@ -3,7 +3,7 @@ import FlutterMacOS
 
 class MainFlutterWindow: NSWindow {
   override func awakeFromNib() {
-    let flutterViewController = FlutterViewController.init()
+    let flutterViewController = FlutterViewController()
     let windowFrame = self.frame
     self.contentViewController = flutterViewController
     self.setFrame(windowFrame, display: true)