Skip sequence parallel operations during eval (#7821)
hi deepspeed!
[Make it possible to evaluate when using sequence parallel in HF Trainer
#43517](https://github.com/huggingface/transformers/pull/43517)
I initially opened a PR in transformers to prevent errors that occur
when running eval with deepspeed sequence parallel applied, but there
was feedback that this should be handled in deepspeed rather than in
transformers or accelerate, so I'm opening this PR here.
If you have any questions, feel free to ask.
