Upgrade emsdk version to v4.0.3

[fs-eire]

Description

Upgrade EMSDK to v4.0.3

File Size Comparison:

Baseline: e666503 [Build]
This change: bb9f747 [Build]

File	Baseline	This Change	Diff
ort-wasm-simd-threaded.jsep.mjs	49,240	44,230	-5,010
ort-wasm-simd-threaded.jsep.wasm	22,921,505	21,236,866	-1,684,639
ort-wasm-simd-threaded.mjs	25,539	20,890	-4,649
ort-wasm-simd-threaded.wasm	11,771,161	10,942,193	-828,968
ort.min.mjs	345,608	345,608	0
ort.bundle.min.mjs	392,960	388,426	-4,534

Motivation and Context

• EMSDK 3.1.62-3.1.74 is not working because of an linker issue (wasm-ld) that causes out-of-memory or crash.
• EMSDK > 3.1.69 requires a change as a post-process of the generated JS file otherwise it will fails onnxruntime-web (as a NPM package) to be consumed in user's web application because of an unexpected webpack behavior.
• EMSDK >= 4.0.1 fixes the out-of-memory issue but brought new issues causes build break of an indirect dependency of ORT (ORT -> ORT-extensions -> dlib).
• EMSDK 4.0.3 introduces a change that allows a previous workaround to be removed.

In this PR, all of the above issues are addressed:

• the linker issue (wasm-ld) is fixed in 4.0.1+
• the post-process is added in onnxruntime_webassembly.cmake as a POST_BUILD event of target onnxruntime_webassembly. It's done by a Node.js script that uses Regex match and replace.
• dlib not working with EMSDK v4:
  • the issue is tracked at [Bug]: Build break in LLVM v19 davisking/dlib#3045
  • Currently no active user is using ORT extension. In this PR, removed ORT extension from the build.
• file gen_struct_info.py is moved from ${DAWN_EMSCRIPTEN_TOOLCHAIN}/tools/maint to ${DAWN_EMSCRIPTEN_TOOLCHAIN}/tools. This helped to remove the patch.tgz for emscripten. This change also requires a change in Dawn, so patched the change needed for Dawn in this PR.