ISO dates with trailing Z throw error when using Python < 3.11

[kulnor]

Describe the bug
When declaring an attribute or slot with a range of datetime, a ValueError: Invalid isoformat string error is raised in Python when running version prior to 3.11

See https://note.nkmk.me/en/python-datetime-isoformat-fromisoformat/#isoformat-string-with-z

Workaround
Replace Z with +00:00 (or use Python >= 3.11)

See https://github.com/nkmk/python-snippets/blob/028c2bcd15e7c776c445ed39e6513801450ed2dc/notebook/datetime_isoformat_timezone.py#L30-L36

Suggestion
In metaamodelcore.py, automatically replace a trailing Z with +00:00 if Python version is < 3.11 (or always)

To reproduce

in Python < 3.11

from datetime import datetime
datetime.fromisoformat("2024-03-20T19:26:08.00Z") # fails
datetime.fromisoformat("2024-03-20T19:26:08.00+00:00") # works
datetime.fromisoformat("2024-03-20T19:26:08.00") # works, but no timezone

In LinkML
(1) Define a slot or attribute with range datetime, such as

created_date:
    description: The date the service was created
    range: datetime 

(2) Parse from a JSON containing with an ISO date with a traillng Z, such as
2024-03-20T19:26:08.000000Z

Expected behavior
No error when parsing the ISO string

[cmungall]

See also:

• metamodelcore DateTime implementation does not fully support ISO-8601 (throws error with Zs) #629
• Add support for Python 3.12 #1704 (comment)