Creates a new synchronous process running command with args.
Optionaloptions: OptionsOptionaloptions: OptionsSends a signal (SIGTERM by default) to the child process.
This has no effect if the process has already exited.
Optionalsignal: number | SignalsBlocks until the child process is ready to emit another event, then returns
that event. This will return an [IteratorReturnResult] with an [ExitEvent]
once when the process exits. If it's called again after that, it will
return {done: true} without a value.
If there's an error starting the child process, the first call to this will throw that error, and the next call will an [ExitEvent] with status 1. If there's an error writing to stdin, the next call to this will throw that error, but the child process won't exit.
A child process that runs synchronously while also allowing the user to interact with it before it shuts down.