[Quantization] Quanto quantizer (#29023)

* start integration

* fix

* add and debug tests

* update tests

* make pytorch serialization works

* compatible with device_map and offload

* fix tests

* make style

* add ref

* guard against safetensors

* add float8 and style

* fix is_serializable

* Fix shard_checkpoint compatibility with quanto

* more tests

* docs

* adjust memory

* better

* style

* pass tests

* Update src/transformers/modeling_utils.py

Co-authored-by: Younes Belkada <49240599+younesbelkada@users.noreply.github.com>

* add is_safe_serialization instead

* Update src/transformers/quantizers/quantizer_quanto.py

Co-authored-by: Younes Belkada <49240599+younesbelkada@users.noreply.github.com>

* add QbitsTensor tests

* fix tests

* simplify activation list

* Update docs/source/en/quantization.md

Co-authored-by: David Corvoysier <david.corvoysier@gmail.com>

* better comment

* Update tests/quantization/quanto_integration/test_quanto.py

Co-authored-by: David Corvoysier <david.corvoysier@gmail.com>

* Update tests/quantization/quanto_integration/test_quanto.py

Co-authored-by: David Corvoysier <david.corvoysier@gmail.com>

* find and fix edge case

* Update docs/source/en/quantization.md

Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* pass weights_only_kwarg instead

* fix shard_checkpoint loading

* simplify update_missing_keys

* Update tests/quantization/quanto_integration/test_quanto.py

Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* recursion to get all tensors

* block serialization

* skip serialization tests

* fix

* change by cuda:0 for now

* fix regression

* update device_map

* fix doc

* add noteboon

* update torch_dtype

* update doc

* typo

* typo

* remove comm

---------

Co-authored-by: Younes Belkada <49240599+younesbelkada@users.noreply.github.com>
Co-authored-by: David Corvoysier <david.corvoysier@gmail.com>
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>
Co-authored-by: Younes Belkada <younesbelkada@gmail.com>

docs/source/en/main_classes/quantization.md

@@ -26,6 +26,10 @@ Learn how to quantize models in the [Quantization](../quantization) guide.
 
 </Tip>
 
+## QuantoConfig
+
+[[autodoc]] QuantoConfig
+
 ## AqlmConfig
 
 [[autodoc]] AqlmConfig