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>

desktop_photo_search/fluent_ui/windows/runner/win32_window.cpp

@@ -60,7 +60,7 @@ class WindowClassRegistrar {
  public:
   ~WindowClassRegistrar() = default;
 
-  // Returns the singleton registar instance.
+  // Returns the singleton registrar instance.
   static WindowClassRegistrar* GetInstance() {
     if (!instance_) {
       instance_ = new WindowClassRegistrar();