fix(version): dockerfile emscripten missing image hash

[erenkucuker]

Summary

Scope of change

• cppjs-core/cpp.js/ (CLI / build orchestration)
• cppjs-plugins/* (bundler / RN integration)
• cppjs-packages/* (a single package family)
• cppjs-samples/*
• website/ (docs)
• scripts/ (repo tooling)
• CI (.github/workflows/)
• Other: ___

Test plan

Validation matrix executed:

• pnpm run check (dist + dep + native version snapshot)
• pnpm --filter=@cpp.js/package-<name>* run build (touched packages)
• pnpm run ci:linux:build (core / plugin changes)
• pnpm run e2e:dev (core / plugin changes)
• pnpm run e2e:prod (core / plugin changes)
• Manual smoke against sample(s): ___
• Other: ___

Output of the most relevant command (paste a short snippet, errors highlighted):

<!-- paste relevant log -->

Risk

• Blast radius:
• Backward compat:
• Native version touched:
• iOS / arm64e / simulator slice changes:
• Multithread / COOP-COEP affected:

Notes for reviewers

Agent assistance

• Agent assisted with this PR (name: ___)
• No AI agent involvement