correctly complete completer when resizing while unmounted and log any errors on resize

lib/widgets/filament_widget.dart

@@ -171,8 +171,10 @@ class _SizedFilamentWidgetState extends State<_SizedFilamentWidget> {
         Duration(milliseconds: (kReleaseMode || Platform.isWindows) ? 10 : 100),
         () async {
       if (!mounted) {
+        completer.complete();
         return;
       }
+      try {
         while (_resizing) {
           await Future.delayed(const Duration(milliseconds: 20));
         }
@@ -183,8 +185,13 @@ class _SizedFilamentWidgetState extends State<_SizedFilamentWidget> {
         _resizeTimer = null;
         setState(() {});
         _resizing = false;
+      } catch (err) {
+        print("Error resizing FilamentWidget: $err");
+      } finally {
         completer.complete();
+      }
     });
+
     return completer.future;
   }