Import ABC from collections.abc for Python 3.10 compatibility.

[tirkarthi]

Import ABC directly from collections was deprecated and removed in Python 3.10. Import from collections.abc for Python 3.10 compatibility.

[tjruwase]

@tirkarthi, thanks for this PR. Can you clarify that this is compatible with python-3.* < 3.10?

[jeffra]

Ah I see a deprecation warning in python 3.8.8 saying: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3, and in 3.9 it will stop working.

Good catch @tirkarthi, thank you.

[jeffra]

@tirkarthi, if you want feel free to add python 3.10 to our setup.py here as well. I think it's good for us to start understanding places where we might break with 3.10.

DeepSpeed/setup.py

Lines 285 to 290 in b61d719

	classifiers=[
	'Programming Language :: Python :: 3.6',
	'Programming Language :: Python :: 3.7',
	'Programming Language :: Python :: 3.8',
	'Programming Language :: Python :: 3.9'
	],