By saving them from any source other than the camera app you’ve configured to not use geo-tagging.
My Photos library contains camera snapshots and screenshots, nothing else.
For what it’s worth, I’m surprised that you never save photos to your phone that you didn’t take yourself. Do people not send you interesting pictures? Pictures of yourself?
I don't even use Photos app on Mac anymore. They've ruined it compared to the old iPhoto. I just keep my photos in folders in Finder.
I don't personally have a strong feeling for or against this particular feature, since I don't use geotagging at all, so it doesn't affect me. I'm neither endorsing nor condemining it offhand. I'll leave it to other people to argue over whether it's a privacy problem. It could be! I just lack the proper perspective on this specific issue.
I actually couldn't get Photos address search to work right in my testing before writing my previous comment, even with a geotagged photo that I just took. So I'm not sure whether I have some setting disabled that prevents it.
The only match was via character recognition of a printed form that I had photographed.
To be clear, I meant that it was a nonissue for me, because I don't geotag my photos (except in that one test). Whether it's an issue for other people, I don't know.
One of the problems with iPhone lockdown is that it's a lot more difficult to investigate how things work technically than on the Mac.