limactl start prevents the terminal from closing after the shell exits

_Disclaimer: An AI helped me debug this. I massaged it a bit by hand though._

### Steps

1. In kitty (a terminal that closes on pty EOF), run `limactl start `.
2. `exit`.

The shell exits and is reaped, but the kitty terminal window stays open.

### Observations

- `lsof /dev/pts/N` and `sudo fuser /dev/pts/N` show no holder of the pty.
- `kill $(pgrep -x qemu-system-x86)` releases the pty; the window closes immediately.
- Redirecting `limactl start`'s stdio (`log 2>&1`) does not change the behavior.
- `setsid limactl start ` avoids it; the window closes on exit.

### Environment

- lima: 2.1.2
- qemu: 7.0.0 (Debian 1:7.0+dfsg-7ubuntu1~jammy1.0)
- host: Linux, kitty, fish