ci: run ABI smoke tests for non-Rust guests

[GianIac]

If you'd like to help with Numax, this is a great place to start, thank you so much for taking a look !

Extend CI build-wasm job to run ABI smoke tests for non-Rust guest examples (where tests exist).

Why

• CI currently validates only part of non-Rust guest coverage
• automated checks prevent drift in guest ABI contracts
• this improves trust in examples used for onboarding

Scope

• update .github/workflows/ci.yml build-wasm job
• execute available smoke tests for guest language examples (C/C++/TinyGo as applicable)
• keep runtime and existing checks unchanged

Done when

• CI runs non-Rust ABI smoke tests and reports failures clearly
• current successful paths remain intact
• workflow remains maintainable and readable

Notes

If a language toolchain is not available by default, document/justify the step clearly.

Thanks again for considering contributing to Numax.