Bug Report: `ksu.spawn` fails to function correctly

[xiliuya]

The ksu.spawn function fails to execute properly, resulting in an exit code of -1 or failing to capture and stream outputs correctly in the current environment.

Test in v438,
Run mode : magsik.
OS: Lineageos 23.2(android 16)
code:

globalThis.spawn_callback_test_123 = {
    stdout: {
        emit: function(event, data) {
            console.log("Kotlin  stdout:", data);
        }
    },
    stderr: {
        emit: function(event, data) {
            console.error("Kotlin stderr:", data);
        }
    },
    emit: function(event, arg) {
        console.log(`Kotlin event: ${event}, args:`, arg);
    }
};

ksu.spawn(
    "ls", 
    JSON.stringify(["-l", "/sdcard"]), 
    JSON.stringify({}), 
    "spawn_callback_test_123"
);