Root cause of this issue is already there in the issue summary. you can see i...

Root cause of this issue is already there in the issue summary. you can see it here.

A dependency chain was there which causes the issue. messages library has dependency of global-styling and drupal.message has the dependency of messages library. That's why we're unable to remove attachments through hook_page_attachments_alter.

I have removed the global library dependency and added the required files to messgaes libarary.

Status is NW, as need to add tests