In #33823, `scripts/package-builds.sh` (which is used by both
`build-packages-dist.sh` and `build-ivy-npm-packages.sh`) was updated to
use `realpath`. It turns out that `realpath` does not exist on macOS, so
the build scripts do not work there.
In order to fix this (and also reduce the likelihood of introducing
similar issues in the future), this commit changes these bash scripts to
Node.js scripts (using [ShellJS](https://github.com/shelljs/shelljs) for
a cross-platform implementation of Unix shell commands where necessary).
PR Close#33854
