Mac build script incorrectly detects Apple Silicon's architecture

[mayoreee]

The Apple Silicon's architecture is incorrectly detected in the build_mac.sh script. The script detects and builds for the architecture as x64 instead of arm64.

Expected Behavior

Correctly detect the Apple Silicon architecture as arm64.

Current Behavior

The current build script uses the os.arch()method for architecture detection. However, this method isn't reliable in recognizing the Apple Silicon architecture.
It should generate prebuilds for arm64 on an Apple Silicon machine, but instead, it generates prebuilds for x64.

Steps to Reproduce (for bugs)

npm run build:mac

Your Environment

• Apple Silicon (M1 mac)
• Platform-host-triplet: arm64-apple-darwin21.2.0
• macOS 12.1