fix: wrong type hinting and redundant 'kwargs' in '_Redis.get()'

Wrong:

class _Redis(Backend):

    async def get(self, key: str, **kwargs) -> Any:
        return await self._client.get(key, **kwargs)

Correct:

class _Redis(Backend):

    async def get(self, key: str) -> bytes:
        return await self._client.get(key)

‘Redis.key()’ signature

Problems:

1. key() does not accept kwargs
2. key() always returns bytes

---

By the way, not related to this issue, but super().__init__() is missing in _Redis.__init__.

[AIGeneratedUsername]

About type hints. You write everywhere something: Union[float, int], but this is redundant because something: float is the same. When you write float, it also says that int is accepted too. See https://www.python.org/dev/peps/pep-0484/#the-numeric-tower

[Krukov]

I’ll close this issue. Some problems already fixed and some should be done with typing support issue https://github.com/Krukov/cashews/issues/66