Yeah, me too.
I'm not sure where Python is getting that 3.20.1 to be honest. It's going to be somewhere in your global Python installation, but if your google-api-core and googleapis-common-protos are up to date, I'm not sure how best to find it.
We do recommend using the Certbot snap or the pip-based virtual environment because they are resilient against weird stuff happening in the OS Python packages. I get that Arch users generally don't want to use snaps, but you can try the latter option, it should work out of the box for you as a replacement, without having to do anything.