After following the steps mentioned in here and installing the new generated xblock, the following deprecation warning appears:
DEPRECATION: Legacy editable install of myxblock-xblock==0.1 from file:///tmp/xblock_development/myxblock (setup.py develop) is deprecated. pip 25.0 will enforce this behaviour change. A possible replacement is to add a pyproject.toml or enable --use-pep517, and use setuptools >= 64. If the resulting installation is not behaving as expected, try using --config-settings editable_mode=compat. Please consult the setuptools documentation for more information. Discussion can be found at https://github.com/pypa/pip/issues/11457