Add platform to package manifest to solve compile errors on macOS 12.2.1

[valeriyvan]

solves #167

please suggest what should be deployment target for linux.

[kateinoigakukun]

Sorry for the late review. It's too much restriction to add a package level min platform version, and I want to keep the scope as minimum as possible. Close by merging https://github.com/swiftwasm/JavaScriptKit/pull/171