This is done in FIX: Do not log 'pull_hotlinked_images' edits in the staff action log · discourse/discourse@67a9894 · GitHub.
Note that moderators can still see logs for private messages that are edited by someone other than the author.
This is tricky to automate - we don’t have any way of knowing whether the existing logs are from “pull hotlinked images”, or have been edited as the system user via the API. @fefrei if you want to wipe the old logs for all system edits on your site, you could run something like this on the console:
UserHistory.where(action: UserHistory.actions[:post_edit], acting_user: Discourse.system_user).destroy_all