🚨🚨🚨 [Refactor] Move third-party related utility files into integrations/ folder 🚨🚨🚨 (#25599)

* move deepspeed to `lib_integrations.deepspeed`

* more refactor

* oops

* fix slow tests

* Fix docs

* fix docs

* addess feedback

* address feedback

* final modifs for PEFT

* fixup

* ok now

* trigger CI

* trigger CI again

* Update docs/source/en/main_classes/deepspeed.md

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* import from `integrations`

* address feedback

* revert removal of `deepspeed` module

* revert removal of `deepspeed` module

* fix conflicts

* ooops

* oops

* add deprecation warning

* place it on the top

* put `FutureWarning`

* fix conflicts with not_doctested.txt

* add back `bitsandbytes` module with a depr warning

* fix

* fix

* fixup

* oops

* fix doctests

---------

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

tests/quantization/bnb/test_mixed_int8.py

@@ -131,7 +131,7 @@ class MixedInt8Test(BaseMixedInt8Test):
         from accelerate import init_empty_weights
 
         from transformers import AutoModelForMaskedLM, Blip2ForConditionalGeneration, MptForCausalLM, OPTForCausalLM
-        from transformers.utils.bitsandbytes import get_keys_to_not_convert
+        from transformers.integrations.bitsandbytes import get_keys_to_not_convert
 
         model_id = "mosaicml/mpt-7b"
         config = AutoConfig.from_pretrained(