Python: Fix typing

[barshaul]

Resolves error on python3.8:

Traceback (most recent call last):
  File “client_example.py”, line 6, in <module>
    from glide import (
  File “/Users/daganh/Library/Python/3.8/lib/python/site-packages/glide/__init__.py”, line 11, in <module>
    from glide.async_commands.redis_modules import json
  File “/Users/daganh/Library/Python/3.8/lib/python/site-packages/glide/async_commands/redis_modules/json.py”, line 23, in <module>
    from glide.redis_client import TRedisClient
  File “/Users/daganh/Library/Python/3.8/lib/python/site-packages/glide/redis_client.py”, line 38, in <module>
    ) -> type[RequestError]:
TypeError: ‘type’ object is not subscriptable