composer require 'drupal/chosen:^4.0' -W throws this error:
Problem 1
- drupal/chosen_lib[dev-3.0.x, 3.0.0, ..., 3.0.x-dev] require drupal/chosen ^3 -> found drupal/chosen[dev-3.0.x, 3.0.0, ..., 3.0.x-dev (alias of dev-3.0.x)] but it conflicts with your root composer.json require (^4.0).
- Root composer.json requires drupal/chosen_lib ^3.0.0 -> satisfiable by drupal/chosen_lib[3.0.0, ..., 3.0.x-dev].How do we upgrade the module?
Closed: works as designed
3.0
Documentation
It is likely that chosen_lib is in your composer.json separately.
In that case chosen_lib needs to be in the require command.
composer require drupal/chosen:4.0 drupal/chosen_lib:4.0 -W