SkJson 5.4.1 — Fix POST Request body (related to mc > 1.20)

Full Changelog: 5.4...5.4.1

command /test:
    trigger:
        set {_request} to prepare POST request on "127.0.0.1:8081/200"
        set {_request}'s header to "Content-Type: application/json"
        set {_request}'s body to json from "{'content': 'discord test'}"
        execute {_request}