onnxruntime

40d36b19 - Improve WebGPU MatMulNBits to support zero pointer for 2bits (#27285)

Improve WebGPU MatMulNBits to support zero pointer for 2bits (#27285) ### Description The existing WebGPU MatMulNBits op does not support zero pointer for 2bits. So it blocks some models. This PR enables the zero pointer support for 2bits support. UT tests are included for coverage.