Drop pkg_resources usage

[gforcada]

See plone/Products.CMFPlone#4126

---

📚 Documentation preview 📚: https://plonerestapi--1882.org.readthedocs.build/

[mister-roboto]

@gforcada thanks for creating this Pull Request and helping to improve Plone!

TL;DR: Finish pushing changes, pass all other checks, then paste a comment:

@jenkins-plone-org please run jobs

To ensure that these changes do not break other parts of Plone, the Plone test suite matrix needs to pass, but it takes 30-60 min. Other CI checks are usually much faster and the Plone Jenkins resources are limited, so when done pushing changes and all other checks pass either start all Jenkins PR jobs yourself, or simply add the comment above in this PR to start all the jobs automatically.

Happy hacking!

[stevepiercy]

When trying to apply the change in conf.py from plone.api to plone.restapi, I was not able to build the docs locally.

      File "/Users/stevepiercy/projects/Plone/documentation/submodules/plone.restapi/lib/python3.13/site-packages/sphinx/config.py", line 616, in eval_config_file
        raise ConfigError(msg % traceback.format_exc()) from exc
    sphinx.errors.ConfigError: There is a programmable error in your configuration file:
    
    Traceback (most recent call last):
      File "/opt/homebrew/Cellar/[email protected]/3.13.2/Frameworks/Python.framework/Versions/3.13/lib/python3.13/importlib/metadata/__init__.py", line 407, in from_name
        return next(iter(cls.discover(name=name)))
    StopIteration
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "/Users/stevepiercy/projects/Plone/documentation/submodules/plone.restapi/lib/python3.13/site-packages/sphinx/config.py", line 601, in eval_config_file
        exec(code, namespace)  # NoQA: S102
        ~~~~^^^^^^^^^^^^^^^^^
      File "/Users/stevepiercy/projects/Plone/documentation/submodules/plone.restapi/docs/source/conf.py", line 40, in <module>
        version = release = version("plone.restapi")
                            ~~~~~~~^^^^^^^^^^^^^^^^^
      File "/opt/homebrew/Cellar/[email protected]/3.13.2/Frameworks/Python.framework/Versions/3.13/lib/python3.13/importlib/metadata/__init__.py", line 987, in version
        return distribution(distribution_name).version
               ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^
      File "/opt/homebrew/Cellar/[email protected]/3.13.2/Frameworks/Python.framework/Versions/3.13/lib/python3.13/importlib/metadata/__init__.py", line 960, in distribution
        return Distribution.from_name(distribution_name)
               ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^
      File "/opt/homebrew/Cellar/[email protected]/3.13.2/Frameworks/Python.framework/Versions/3.13/lib/python3.13/importlib/metadata/__init__.py", line 409, in from_name
        raise PackageNotFoundError(name)
    importlib.metadata.PackageNotFoundError: No package metadata was found for plone.restapi

I have no idea why it doesn't work the same.

I also noticed the file https://github.com/plone/plone.restapi/blob/main/src/plone/__init__.py is the same in both packages. I don't know if it should also be included in this PR to remove that instance of pkg_resources, or if it's related to not being able to build docs.

It's not absolutely necessary to use the change in conf.py from plone.api in plone.restapi, but it would be nice not to have to remember to manually update the version number when making a release going forward.

[davisagli]

@stevepiercy Fixed in 7677ce8 (plone.restapi needs to be actually installed in the virtualenv where the docs commands are, in order to look up its version this way).

The use of pkg_resources in __init__.py files is how setuptools namespaces are declared, and they need to be removed in a coordinated fashion with other packages as planned in plone/Products.CMFPlone#3928

[davisagli]

@jenkins-plone-org please run jobs

[stevepiercy]

Docs look good on RTD. Thank you!