* ggml-webgpu: Add unary op (SQR, SQRT, SIN, COS) support. * Fix to cast the src value to f32 before sin/cos computing.
* Fix GGML_MEM_ALIGN to 8 for emscripten. * Add a comment explaining the need for GGML_MEM_ALIGN == 8 in 64-bit wasm with emscripten