DocList raises exception for type object. #1828

Initial Checks

• I have read and followed the docs and still think this is a bug

Description

This commit introduced a check to verify that DocList is not used with an object:

        if (
            isinstance(item, object)
            and not is_typevar(item)
            and not isinstance(item, str)
            and item is not Any
        ):
               raise TypeError('Expecting a type, got object instead')

This is quite a broad condition (it breaks things like DocList[TorchTensor], or nested DocList[DocList[...]] for me for instance) as:

• Almost everything will be an object so the first line if almost a catch-all.
• is_typevar only checks for TypeVar objects.

Should this not check as well for something not isinstance(item, type) instead of not is_typevar to allow for classes ?
This way only non class objects (like instances of class object that are not classes themselves) will raise the TypeError.

Example Code

from docarray import DocList
from docarray.typing import TorchTensor
test = DocList[TorchTensor]

Python, DocArray & OS Version

0.39.1

Affected Components

• Vector Database / Index
• Representing
• Sending
• storing
• multi modal data type