Remove "SatNOGS (for Rasperry Pi 4)" image from rpi-imager repo
The Raspberry Pi 4 is supported by the original SatNOGS Image since 2022091000, which is based on 2022-04-04-raspios-bullseye
(merge commit). Thus the "SatNOGS (for Raspberry Pi 4)" image offered in the rpi-imager repo is not required anymore.
Remove the respective entry from pi-imager/additional_images.json.