[js/web] update default export to include webgpu (#22754)
### Description
This PR changes the following exports:
- `onnxruntime-web` now is same to `onnxruntime-web/webgpu`.
- `onnxruntime-web/webgpu` is deprecating.
### Migration instructions:
- use `onnxruntime-web` instead of `onnxruntime-web/webgpu`.
- use `onnxruntime-web/wasm` if want to use onnxruntime-web without
webgpu/webnn.
### Export table
| file name | export entry | includes WASM | includes JSEP (WebGPU &
WebNN) | includes WebGL
| ------------- | ------------- | ----- | ----- | -----
| ort.all.min.js<br/>ort.all.js<br/>ort.all.min.mjs<br/>ort.all.mjs |
`onnxruntime-web/all` | ✔️| ✔️| ✔️
| ort.min.js<br/>ort.js<br/>ort.min.mjs<br/>ort.mjs | `onnxruntime-web`
| ✔️| ❌ --> ✔️| ✔️ -->❌
|
ort.webgpu.min.js<br/>ort.webgpu.js<br/>ort.webgpu.min.mjs<br/>ort.webgpu.mjs
| `onnxruntime-web/webgpu` | ✔️ | ✔️ |❌
| ort.wasm.min.js<br/>ort.wasm.js<br/>ort.wasm.min.mjs<br/>ort.wasm.mjs
| `onnxruntime-web/wasm` | ✔️ | ❌ |❌
