set constant=True for pydantic types (resolves ambiguity in model val…

…idation)

change datatype for Number to Union of int and float

Use StrictFloat and StrictInt

Use const=True for Field type_ for Schema.org model discrimination

replace ISO8601Date with datetime

keyword args for SchemaOrgBase.py (fixes type checking bug in pylance…

…/VSCode)

keyword args for SchemaOrgBase.py (fixes type checking bug in pylance…

…/VSCode)

keyword args for SchemaOrgBase.py (fixes type checking bug in pylance…

…/VSCode)

GitHub actions: only run actions on master

update models, for new release

fix imports for ISO8601 date

fix imports for ISO8601 date