Add support for Python 3.14

[mattkjames7]

Once support has been added to pymgclient (see memgraph/pymgclient#81), we can also try adding it here.

[atom8be]

_____________________________________________
ERROR collecting tests/test_db_graph.py
_____________________________________________
tests/test_db_graph.py:6: in <module>
    from app.db.schema import Module
src/app/db/schema.py:4: in <module>
    class CodeElement(Node):
.venv/lib/python3.14/site-packages/gqlalchemy/models.py:558: in __new__
    cls = super().__new__(mcs, name, bases, namespace, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.venv/lib/python3.14/site-packages/pydantic/v1/main.py:221: in __new__
    inferred = ModelField.infer(
.venv/lib/python3.14/site-packages/pydantic/v1/fields.py:504: in infer
    return cls(
.venv/lib/python3.14/site-packages/pydantic/v1/fields.py:434: in __init__
    self.prepare()
.venv/lib/python3.14/site-packages/pydantic/v1/fields.py:544: in prepare
    self._set_default_and_type()
.venv/lib/python3.14/site-packages/pydantic/v1/fields.py:576: in _set_default_and_type
    raise errors_.ConfigError(f'unable to infer type for attribute "{self.name}"')
E   pydantic.v1.errors.ConfigError: unable to infer type for attribute "docstring"
======== warnings summary ========
.venv/lib/python3.14/site-packages/gqlalchemy/__init__.py:17
.venv/lib/python3.14/site-packages/gqlalchemy/__init__.py:17: UserWarning: Core Pydantic V1 functionality isn't compatible with Python 3.14 or greater.
    from pydantic.v1 import validator  # noqa F401