flutter clean cant delete .dart_tool

[asafgo]

Since the following version on windows 11

Flutter 3.38.1 • channel stable • https://github.com/flutter/flutter.git
Framework • revision b45fa18946 (8 days ago) • 2025-11-12 22:09:06 -0600
Engine • hash 78c3c9557e50ee7c676fa37562558c59efd8406a (revision b5990e5ccc) (13 days ago) • 2025-11-12 21:08:24.000Z
Tools • Dart 3.10.0 • DevTools 2.51.1

When running command flutter clean I get an error:
Failed to remove C:\aaa\bbb.dart_tool. A program may still be using a file in the directory or the directory itself. To find and stop such a
program, see: https://superuser.com/questions/1333118/cant-delete-empty-folder-because-it-is-used

checking with File Locksmith I see a lot of dart.exe processes locking the folder .dart_tool