Run dart fix in lib

lib/widgets/filament_gesture_detector.dart

@@ -1,8 +1,6 @@
-import 'dart:async';
 import 'dart:io';
 
 import 'package:flutter/foundation.dart';
-import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_filament/widgets/filament_gesture_detector_desktop.dart';
 import 'package:flutter_filament/widgets/filament_gesture_detector_mobile.dart';

lib/widgets/filament_gesture_detector_desktop.dart

@@ -49,7 +49,7 @@ class _FilamentGestureDetectorDesktopState
   ///
   ///
   ///
-  bool _scaling = false;
+  final bool _scaling = false;
 
   bool _pointerMoving = false;
 
@@ -78,7 +78,7 @@ class _FilamentGestureDetectorDesktopState
 
     // we don't want to end the zoom in the same frame, because this will destroy the camera manipulator (and cancel the zoom update).
     // here, we just defer calling [zoomEnd] for 100ms to ensure the update is propagated through.
-    _scrollTimer = Timer(Duration(milliseconds: 100), () async {
+    _scrollTimer = Timer(const Duration(milliseconds: 100), () async {
       await widget.controller.zoomEnd();
     });
   }

lib/widgets/filament_widget.dart

@@ -110,8 +110,7 @@ class _SizedFilamentWidget extends StatefulWidget {
   final FilamentController controller;
 
   const _SizedFilamentWidget(
-      {super.key,
-      required this.width,
+      {required this.width,
       required this.height,
       this.initial,
       required this.controller});