How to find out if Raspberry PI Linux OS needs a reboot

When you use the apt command to update the Raspberry Pi OS, no notification indicates whether you need to reboot the Raspberry Pi 3 or 4 for Linux kernel updates. So say you have a lab of 4 RPi4 and managing updates using ansible, then you need an automated way to find out if a reboot is required to load a new Linux kernel on your Raspberry Pi OS.