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 putty, had a general exception to keep using it in Fedora 31. Now, the dependency should be removed.
Switching to Python 3 seemed easy to me (though I don't necessarily
know much about putty). So I opened a pull request: https://src.fedoraproject.org/rpms/putty/pull-request/2
Could you merge it?
If not, 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.