[`BitsAndBytesConfig`] Warning for unused `kwargs` & safety checkers for `load_in_4bit` and `load_in_8bit` (#29761)
* added safety checkers for load_in_4bit and load_in_8bit on init, as well as their setters
* Update src/transformers/utils/quantization_config.py
typo correction for load_in_8bit setter checks
Co-authored-by: Younes Belkada <49240599+younesbelkada@users.noreply.github.com>
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Co-authored-by: Younes Belkada <49240599+younesbelkada@users.noreply.github.com>