DEPRECATION: update pydantic methods

[Segelzwerg]

Fix the following:

• tests/whist_core/cards/test_card.py::CardTestCase::test_dict
  /home/runner/work/Whist-Core/Whist-Core/tests/whist_core/cards/test_card.py:25: DeprecatedWarning: dict is deprecated as of Use model_dump instead. Will be removed in V1..
  self.assertEqual({'suit': 'hearts', 'rank': 'ace'}, self.card.dict())

• tests/whist_core/game/test_trick.py::TrickTestCase::test_trick_json_after_player
  The dict method is deprecated; use model_dump instead. Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.6/migration/
  warnings.warn('The dict method is deprecated; use model_dump instead.', category=PydanticDeprecatedSince20)

• tests/whist_core/game/test_trick.py::TrickTestCase::test_dict_trump

  PydanticDeprecatedSince20: The dict method is deprecated; use model_dump instead. Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.6/migration/
  warnings.warn('The dict method is deprecated; use model_dump instead.', category=PydanticDeprecatedSince20)

• tests/whist_core/session/test_table.py::TableTestCase::test_table_random_matcher_from_json_generic
  PydanticDeprecatedSince20: The __fields__ attribute is deprecated, use model_fields instead. Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.6/migration/