Python 2 reached upstream end-of-life in January 2020. In Fedora Rawhide, it's now provided from the compat package `python27`.
Packages that only use Python 2 at build time, like flatpak-rpm-macros, had a general exception to keep using it in Fedora 31. Now, the dependency should be removed.
Let us know if you need any help investigating or removing the dependency. (There are dozens of packages like this, so we didn't investigate this one thoroughly. We assume you know the package best.)

If it's possible that the dependency won't be removed in Fedora 33. Please request a FESCo exception. You can refer to the exception for mercurial as an example: https://pagure.io/fesco/issue/2243
It's good to mention:

- What is the reason for the Python 2 build dependency?

- What are the upstream/community plans/timelines regarding Python 2?

- What is the guidance for porting the build to Python 3? (Assuming that there is someone who generally knows how to port to Python 3, but doesn't know anything about the particular package, what are the next steps to take?)

If you need anything from us, or something is unclear, please mention it here.