onnxruntime

063491ce - [webgpu] add usage of ReadonlyAllocator for WebGPU EP (#25690)

[webgpu] add usage of ReadonlyAllocator for WebGPU EP (#25690) ### Description add usage of `ReadonlyAllocator` for WebGPU EP ### Motivation and Context `ReadonlyAllocator` is added in #25348 to allow an EP to register a separated allocator only use for initializers. WebGPU EP already has different handling to initializers and non-initializers, and this change makes WebGPU EP to use the preferred way to deal with it. Now the allocator depends on the `OrtAllocatorType` instead of the session initialization status.