js - deprecated dependency

[lea108]

First - thank you for keep maintaining this package.

This package depends on flutter_secure_store which in term still uses the js package. The js package also comes via encrypt 5.0.3 -> pointycastle 3.9.1.

This causes --wasm builds to fail.

It looks like encrypt is currently unmaintained. pointycastle does have a 4.0.0 release what claims to have removed the js package dependency.