onnxruntime

9fd70130 - Fix WebGPU ConvTranspose shader bugs for non-vectorizable input channels (#27749)

Fix WebGPU ConvTranspose shader bugs for non-vectorizable input channels (#27749) ## Description Fix two bugs in the WebGPU ConvTranspose shader code generation (conv_backprop.cc) in the `pack_input_as4_` code path when `a_components_ == 1` (triggered when input channels per group is not divisible by 2 or 4, e.g., 5 or 7). ### Bug 1: Wrong offset for weight reads Weight values were read using `x_offset` (the input/dy tensor offset) instead of `w_offset` (the weight tensor offset), producing incorrect convolution results. ### Bug 2: Missing weight multiplication in remainder loop The remainder loop (handling leftover channels when `inputChannelsPerGroup` is not a multiple of 4) was adding raw input values to `dotProd` without multiplying by the corresponding weight values. ## Motivation and Context The `inChannels = 5` and `inChannels = 7` test cases in `conv-transpose.jsonc` were failing because these channel counts aren't divisible by 2 or 4, triggering the buggy `a_components_ == 1` branch. Cases like `inChannels = 6` (`a_components_ = 2`) and `inChannels = 8` (`a_components_ = 4`) were unaffected. ## Testing All 22 conv-transpose WebGPU tests now pass: ``` npm test -- op conv-transpose.jsonc -b=webgpu -e=node 22 passing (23s) ``` Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>