Odoo 14 not using lessc. it seems you have custom module still using less.

install nodejs, reboot (to update the PATH) and install less: 

then run the command in windows command:

C:\> npm install -g less

The style compilation failed, see the error below. Your recent actions may be the cause, please try reverting the changes you made.

Error: ".small" failed to @extend "small".
       The selector "small" was not found.
       Use "@extend small !optional" if the extend should be able to fail.
        on line 47 of home/rubies/odoo/odoo16/addons/web/static/lib/bootstrap/scss/_type.scss

please

Thanks everyone, it worked for me