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 unicorn, had a general exception to keep using it in Fedora 31. Now, the dependency should be removed. It seems that Python 3 support was already merged upstream (for unicorn 1.0.2): https://github.com/unicorn-engine/unicorn/commit/f4cc35a24afb0b74f5dec2235567b393c1289bb2#diff-7b01237564ed5fb3043693851760e79e If it's possible that the Python 2 build dependency won't get removed in Fedora 33, please let us know; the package will need a FESCo exception. If you need anything from us, or something is unclear, please mention it here.
Fixed in latest release.