We've been using gitea for 6 years, and I see no reason to migrate anywhere at this moment. Gitea sees faster development and has more features (even though many patches flow to Forgejo — the reverse is impossible due to license restrictions).
It is possible to migrate from 1.22 to Forgejo simply by changing the binary, and downgrading from 1.24 to 1.23, and from 1.23 to 1.22 is possible if you know your way around PostgreSQL and have a spare hour. I always write downgrade scripts for each release and test them before upgrading Gitea to make sure that I can always back out and move to Forgejo if Gitea folds. Haven't seen much reason to do it up to this moment, though.
edit: for example, here's a 1.23 → 1.22 downgrade script; I don't have access to 1.24 → 1.23 atm:
It is possible to migrate from 1.22 to Forgejo simply by changing the binary, and downgrading from 1.24 to 1.23, and from 1.23 to 1.22 is possible if you know your way around PostgreSQL and have a spare hour. I always write downgrade scripts for each release and test them before upgrading Gitea to make sure that I can always back out and move to Forgejo if Gitea folds. Haven't seen much reason to do it up to this moment, though.
edit: for example, here's a 1.23 → 1.22 downgrade script; I don't have access to 1.24 → 1.23 atm:
https://paste.debian.net/plainh/7d8cab27