onnxruntime

07337333 - [Quant tool] Handle input models with pre-quantized weights (#22633)

[Quant tool] Handle input models with pre-quantized weights (#22633) ### Description Allows the QDQ quantizer to handle input models that already have some pre-quantized weights. In this case, the qdq quantizer will properly skip/handle the pre-quantized weights. Also handles an operator (e.g., Conv) with a pre-quantized weight and a float bias. The tool will read the pre-quantized weight's quantization scale to compute the bias's scale (`bias_scale = input_scale * weight_scale`). Input model (pre-quantized Conv weight):  Output QDQ model (everything is quantized):  ### Motivation and Context Customers may use external tools to quantize some weights (e.g., int4 for Conv/MatMul). The qdq quantizer should still be able to quantize the rest of the model (float weights and activations) in this case.