python 3.8 does not seem to work

[wjs20]

I installed the package with python 3.8 and I got the error message below.

| python
Python 3.8.10 (default, Nov 14 2022, 12:59:47)
[GCC 9.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from platechain.constants import *
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/ws/git/platechain/src/platechain/__init__.py", line 1, in <module>
    from platechain.chain import chain, parse_plates
  File "/home/ws/git/platechain/src/platechain/chain.py", line 38, in <module>
    class ParsePlateRequest(BaseModel):
  File "/home/ws/.cache/pypoetry/virtualenvs/platechain-H7xkWrxE-py3.8/lib/python3.8/site-packages/pydantic/_internal/_model_construction.py", line 183, in __new__
    set_model_fields(cls, bases, config_wrapper, types_namespace)
  File "/home/ws/.cache/pypoetry/virtualenvs/platechain-H7xkWrxE-py3.8/lib/python3.8/site-packages/pydantic/_internal/_model_construction.py", line 418, in set_model_fields
    fields, class_vars = collect_model_fields(cls, bases, config_wrapper, types_namespace, typevars_map=typevars_map)
  File "/home/ws/.cache/pypoetry/virtualenvs/platechain-H7xkWrxE-py3.8/lib/python3.8/site-packages/pydantic/_internal/_fields.py", line 99, in collect_model_fields
    type_hints = get_cls_type_hints_lenient(cls, types_namespace)
  File "/home/ws/.cache/pypoetry/virtualenvs/platechain-H7xkWrxE-py3.8/lib/python3.8/site-packages/pydantic/_internal/_typing_extra.py", line 212, in get_cls_type_hints_lenient
    hints[name] = eval_type_lenient(value, globalns, localns)
  File "/home/ws/.cache/pypoetry/virtualenvs/platechain-H7xkWrxE-py3.8/lib/python3.8/site-packages/pydantic/_internal/_typing_extra.py", line 224, in eval_type_lenient
    return typing._eval_type(value, globalns, localns)  # type: ignore
  File "/usr/lib/python3.8/typing.py", line 270, in _eval_type
    return t._evaluate(globalns, localns)
  File "/usr/lib/python3.8/typing.py", line 518, in _evaluate
    eval(self.__forward_code__, globalns, localns),
  File "<string>", line 1, in <module>
TypeError: unsupported operand type(s) for |: 'type' and 'NoneType'

Apparently support for expressing unions of types using the pipe operater was only introduced in python 3.10. So I think this needs to be reflected in the requirements file (At the moment it is set to ^3.8)