Based on the notion that WiFi is available and this is a very light use-case, you could get away with a Pi Zero W (the 'W' is WiFi version).
The major elements of this are:
Acquire & assemble hardware
Download Raspberry Pi OS (Lite)
Copy OS image to microSD card
Configure to allow SSH access and also WiFi configuration
Create camera capture job (via ...
If you have a look in the /boot/overlays/README file you will see that the folk at RPF/RPT have tried to sort this out by actually renaming the file:
This overlay has been renamed disable-bt
Unfortunately, the internet never keeps up 😢 so you will not find a pi4-disable-bt option. You can continue to use the pi3 command but I would use the disable-bt ...