Remove trust_remote_code=True tests from bnb quantization tests (MPT now integrated) (#38206)
bnb quant tests: remove obsolete trust_remote_code test
The MPT model is now natively integrated in Transformers and no longer requires trust_remote_code=True. This removes the failing test_get_keys_to_not_convert_trust_remote_code and related usage, which depended on remote code and caused CI issues due to missing dependencies (e.g., triton_pre_mlir).