Installing python3-devel currently brings in:
- annobin
- dwz
- efi-srpm-macros
- fpc-srpm-macros
- ghc-srpm-macros
- gnat-srpm-macros
- go-srpm-macros
- nim-srpm-macros
- ocaml-srpm-macros
- openblas-srpm-macros
- perl-srpm-macros
- python-rpm-macros
- python-srpm-macros
- python3-rpm-generators
- python3-rpm-macros
- qt5-srpm-macros
- redhat-rpm-config
- rust-srpm-macros
For somebody who needs python3-devel to build extension modules,
those are all useless, so we conditionalize it on rpm-build.
Based on the reason for setuptools dependency, we do the same here
(but note that python3 already recommends it).
e9ba67b74b