Adding checkpoint backwards compatibility tests after 0.23.0 release

[bigning]

What does this PR do?

Following the release processing doc, this is the last step to add checkpoint backward compatibility tests

Daily test: https://github.com/mosaicml/composer/actions/runs/9407180074

[snarayan21]

Can you run dailies and make sure they pass before merging this? And it would be helpful to link the daily test run in a comment

[mvpatel2000]

LGTM. Agree with Saaketh, can we fire off dailies to verify?

[bigning]

@mvpatel2000 , @snarayan21 sounds good. I will fire Daily test after the CI issues are resolved.

[bigning]

Can you run dailies and make sure they pass before merging this? And it would be helpful to link the daily test run in a comment

The daily test indeed failed test_fsdp_load_old_checkpoint. It seems expected because 2.1/2.2 can't load checkpoint saved by 2.3. I see it skipped composer 0.22.0. I guess I should do a similar change here. @snarayan21 , is my understanding correct ? I started a new daily test.

[snarayan21]

@bigning yes, that's correct. we don't need to ensure that torch 2.1 and 2.2 users can load torch 2.3 checkpoints, only that torch 2.3 users can load old checkpoints for backwards compat.