Remove `child_process` dependency for improved browser compatibility

[WillianAgostini]

⭐ Suggestion

Discussion #960

Currently, node-cron depends on child_process to execute string-based commands, which prevents it from being used in browser environments.

I propose completely removing the child_process dependency to enhance browser compatibility and make node-cron more versatile across different platforms.

💻 Use Cases

Running node-cron in a browser-based environment.

❌ Related Problems

#538
#426
#345
#333
#299
#171

[Func86]

For complete browser support, the impact of chained JS timers throttling should be assessed, and worker-timers or similar packages should be used if needed.