The privacy panel, from the Settings app, have security-related subpanels like Screen Lock and Device Security (GNOME 43). Also, privacy can also be security; depending on your threat model, even more. However, the panel name doesn’t fit to all of this. This would make easier for users to know where security settings are located.
Personally, I would place the “Device Security” pane with the “About” pane. It has no configurable settings (at least not directly like the other settings) and instead gives information about the security status of the device.