chore: add support for python 3.12

[Silvanoc]

Upgrading greenlet version to have support for Python 3.12. See here for more information: python-greenlet/greenlet#323

⚠️ WARNING! This PR is removing support for Python 2.7, 3.5 and 3.6.

Closes #45

[cmungall]

Did you intend to only update the lock file? Without changes in pyproject.toml these could be overwritten in future PRs

[Silvanoc]

Did you intend to only update the lock file? Without changes in pyproject.toml these could be overwritten in future PRs

The dependency on greenlet is not being explicitly declared in the pyprojects.toml file, that's why I've only updated the lock file.

I would say, that either we add a test for Python v3.12 or we declare that dependency in the pyprojects.toml file to avoid that the change can get reverted in the future.

I'm not sure either if the demand for this PR really exists. I've only stumbled upon it and thought it would make sense to add support for the latest Python version.

[Silvanoc]

Looking at the tests I can tell that no validation is taking place for Python 2.7, 3.5 and 3.6 anyway. So removing support for those Python releases is probably not so bad.

[Silvanoc]

Trying out the testing approach proposed here, marking as draft until tests run for Python v.3.12.

[Silvanoc]

Following draft PRs on linkml-runtime and linkml will help distributing the support for Python 3.12 to those components:

• Add support for Python 3.12 linkml-runtime#286
• Add support for Python 3.12 linkml#1704

[Silvanoc]

Thanks to #54 from @cmungall I got the solution to the issue that was blocking this PR. I've integrated his commit (to keep attribution), but updated the Poetry lock accordingly extending his commit.

It's now ready for integration, removing the 'Draft' marker and retriggering review.

[Silvanoc]

@sierra-moxon we have already 3 prefixmaps PRs with some overlapping:

• chore: add support for python 3.12 #53 (this one, which has integrated the single commit from Remove pydantic pinning #54 and validates support for Python 3.12)
• Remove pydantic pinning #54 (which provided the solution to overcome an issue I had in chore: add support for python 3.12 #53)
• update dependencies #55 (which doesn't have a sucessful pipeline, but updates more packages than chore: add support for python 3.12 #53 and Remove pydantic pinning #54)

It would be meaningful to merge at least one of them and then reconsider if something is left over that should be covered by a 2nd one. #54 is in any case covered by #53 and #55.

I personally would go for this one (not only because it's mine, but because it validates support for Python 3.12 and has a "green" pipeline), rebasing #55 and reconsidering if what's left is needed or not.