fix(emscripten): ensure EMSDK setup completes before WASM compilation

[kassane]

closes #53

based on: https://github.com/floooh/sokol-zig-imgui-sample/blob/main/build.zig

[floooh]

IIRC the way it is supposed to work in the sokol-zig build.zig is that the sokol C library depends on the Emscripten setup step, and then all other C libraries depend on the sokol library.

E.g. the lib here is the sokol C library:

https://github.com/floooh/sokol-zig/blob/935ad0e05eeb6c223d06dcdd16a155c6be8ff49d/build.zig#L202-L204

...and the in the sokol-zig-imgui-sample project, the cimgui lib depends on sokol:

https://github.com/floooh/sokol-zig-imgui-sample/blob/4e09e59c95e04399a04d9e2f39aeb03057813aec/build.zig#L75

...so basically, Emscripten setup finishes first, then the sokol C library is compiled, and then all other C libraries.

[floooh]

Oh... the errors here (assert.h not found):

https://github.com/kassane/sokol-d/actions/runs/13225929376/job/36916768510

...look entirely different then the CI error in this PR (those are all linker errors):

https://github.com/kassane/sokol-d/actions/runs/13265008351/job/37030179876

[kassane]

Oh... the errors here (assert.h not found):

https://github.com/kassane/sokol-d/actions/runs/13225929376/job/36916768510

...look entirely different then the CI error in this PR (those are all linker errors):

https://github.com/kassane/sokol-d/actions/runs/13265008351/job/37030179876

Exactly! ldc2 replace libsokol to libimgui config. 🤦‍♂️ (I'll fix)

---edit

Why windows works?

[kassane]

Evaluating the current build process involving imgui:

• build libsokol
• build libimgui + cimgui (if enabled)
• build D example(s) - get libsokol and libimgui + cimgui.h (dcimgui.d)*

*ldc2/ldmd2 requires reading the header to autogenerate imgui-bindings. Unlike libsokol which has bindings generated in the sokol-upstream. Also ldc2/ldmd2 get all includes + flags/defines from libsokol!

[kassane]

Ok. I need help (MacOS user)!!

[kassane]

Finally 96a06db ✔️ (need review)

[kassane]

Why dub in windows tried linking sokol_imgui on non-imgui samples?
https://github.com/kassane/sokol-d/actions/runs/13271341447/job/37051226526?pr=54#step:6:31