Updates for pydantic v2

[dougiesquire]

Change Summary

This PR implements changes required for Intake-ESM to update to the recently-released pydantic v2. I'd appreciate someone taking a close look at this as I'm not a pydantic expert, especially v2.

Related issue number

Closes #617

Checklist

• Unit tests for the changes exist
• Tests pass on CI

[dougiesquire]

Agh, the autodoc_pydantic Sphinx extension does not support pydantic v2 and it doesn't look like it will any time soon, see mansenfranzen/autodoc_pydantic#146.

What to do?

• Update Intake-ESM to use pydantic v2 and lose the autodoc_pydantic extension, resulting in the API section of the docs being poorly formatted. (Unfortunately, I can't generate a version of the docs atm to demonstrate what this would look like as the docs rely on ecgtools which also requires pydantic updates, see Updates for pydantic v2 ncar-xdev/ecgtools#164. Yes, we're in a state right now where Intake-ESM and ecgtools are both failing because the other is failing),
• Pin pydantic to v1 in Intake-ESM (and ecgtools).

[dougiesquire]

I tried to disable the autodoc_pydantic extension and temporarily change the CI doc environment to install ecgtools from ncar-xdev/ecgtools#164 so the docs would build in this PR, but there's another issue with the docs that makes the build fail intermittently.

Instead, here's is a screenshot of the API docs for a pydantic object rendered without the autodoc_pydantic extension. I think they look fine. Let me know if you agree and I'll finish up this PR.

[mgrover1]

I tried to disable the autodoc_pydantic extension and temporarily change the CI doc environment to install ecgtools from ncar-xdev/ecgtools#164 so the docs would build in this PR, but there's another issue with the docs that makes the build fail intermittently.

Instead, here's is a screenshot of the API docs for a pydantic object rendered without the autodoc_pydantic extension. I think they look fine. Let me know if you agree and I'll finish up this PR.

Thanks so much @dougiesquire for the hard work here - I think this looks fine and we can proceed!

[dougiesquire]

Ready for review @mgrover1

Note, the docs build is still failing because of:

1. the pydantic changes required in ecgtools
2. another intermittent issue when running docs/source/how-to/build-a-catalog-from-timeseries-files.md.

I suggest:

• merge this PR. This should fix the failing tests in Updates for pydantic v2 ncar-xdev/ecgtools#164
• merge Updates for pydantic v2 ncar-xdev/ecgtools#164. This should fix issue 1 above.
• address issue 2 in another PR

[mansenfranzen]

@dougiesquire You can now test the new autodoc_pydantic version supporting pydantic v2 via pip install autodoc_pydantic==2.0.0. The dev docs already showcase v2 support (see here). Migration guide is available here.

Any feedback is more than appreciated. The current autodoc_pydantic version 2.0.0 on pypi remains yanked for one week until final release.