🚑 docker_dev_start and docker_pylint: do not duplicate mount point for songs when they are correctly defined in python_packages.

--user is not compatible with the use of venv.

Also add a workaround a hatchling/setuptools-scm bug.

📚 update package classifiers

Based on Odoo 15 - requirements are almost the same.

It leaves the installed module path alone and also avoids ending up with empty directory in the odoo clone’s
odoo/addons directory.