Llama et al. / FSDP : Fix breaking change in 4.40 for FSDP (#31161)
* fix llama fsdp
* fixup
* adding FSDP tests for CPU offloading
* fixes
* fix tests
* fix tests
* add it for mixtral
* propagate the changes on other models
* Update src/transformers/models/phi/modeling_phi.py
* Delete utils/testing_scripts/fsdp_cpu_offloading.py
Remove script - FSDP + CPU offloading it tested in the test suite
* Delete utils/testing_scripts/dummy_fsdp_config.yml
* Update + add cache_positions docstring
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Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>