[web] support JSPI build (#26095)
### Description
This PR introduces the support for building WebGPU EP with JSPI support.
When build with `--enable_wasm_jspi`, it does the following:
- Use `JSPI` instead of `ASYNCIFY`
- Use WebAssembly EH (-fwasm-exceptions) instead of Emscripten
exceptions
### Motivation and Context
Using JSPI with wasm exceptions help to have:
- better performance (reduced CPU overhead)
- smaller binary size (no extra generated ASYNCIFY code)
- faster build time
