refactor(ci): use native ARM64 runners instead of Docker+QEMU

[andrescera]

Summary

Simplifies CI workflows by replacing Docker+QEMU emulation with native ARM64 runners.

Changes

• build-check.yml: Removed Docker/QEMU, use native ubuntu-24.04-arm64
• publish-release.yml: Same simplification for release builds
• Direct CMake builds instead of containerized builds
• Faster, more reliable ARM64 builds

Benefits

• 2-3x faster ARM64 builds (native vs QEMU emulation)
• Simpler workflows (removed ~50% of setup code)
• More reliable (no QEMU compatibility issues)
• Easier debugging (direct build output)

Test Plan

• Updated workflows pushed
• CI passes on both amd64 and arm64
• Build artifacts verified