To include the CHANGELOG.md file in your Sphinx documentation, you can use the m2r2 extension to convert the Markdown file to reStructuredText format, which Sphinx can process.

First, install the m2r2 package by adding it to your pyproject.toml file:

[build-system]
requires = [
    # ... other dependencies ...
    "m2r2"
]

Next, update your docs/conf.py file to include the m2r2 extension:

extensions = [
    # ... other extensions ...
    'm2r2',
]

Create a new file named changelog.rst in your docs/source directory with the following content:

Changelog
=========

.. mdinclude:: ../../CHANGELOG.md

This file will include the content of the CHANGELOG.md file in your Sphinx documentation.

Finally, add a reference to the changelog.rst file in your docs/source/index.rst file:

.. toctree::
   :maxdepth: 2
   :caption: Contents:

   # ... other files ...
   changelog

Now, the CHANGELOG.md file will be included in your Sphinx documentation. The updated .gitlab-ci.yml file remains the same as in the previous response.