add isodate as dependency

[will-0]

isodate used since a1a6b48, but not added as dependency.

[dalito]

isodate is currently included via rdflib. rdflib specifies it currently as isodate = {version=">=0.7.2,<1.0.0", python = "<3.11"}.

In linkml-runtime we should also add it only for python <3.11.

[will-0]

Makes sense. How does it work if you're using higher python versions then? My project was failing due to the missed dependency on python 3.12

[dalito]

Ah. The import should also depend on the Python version. I should have done that in #357 (surprising that the tests passed). Can you add the conditional import to your PR? isodate is only imported here

linkml-runtime/linkml_runtime/utils/metamodelcore.py

Line 10 in 4f31524

import isodate

[dalito]

@will-0 - FYI: I submitted #380 to solve the issue by making the import Python version dependent.