onnxruntime

f67f7482 - Fix WebGPU GatherBlockQuantized dispatch failure for empty indices (#29030)

Fix WebGPU GatherBlockQuantized dispatch failure for empty indices (#29030) ### Description `GatherBlockQuantized` on WebGPU computes the dispatch size as `ceil(output_size / 64)`, which is 0 when the gather output is empty (e.g. an empty indices tensor), and `NormalizeDispatchGroupSize` rejects the (0, 1, 1) dispatch. Return early for an empty output instead, matching other WebGPU kernels. Adds `GatherBlockQuantizedOpTest.WebGpu_EmptyIndices_8Bits_Uint8`. ### Motivation and Context Fixes #28772.