[WIP] support variable %python in %python_module

[bnavigator]

This allows us to put boolean rpm dependencies into %{python_module } referring to the expanded python flavor.

Example package

BuildRequires:  %{python_module ABCD36 and %python-base <= 3.6}
BuildRequires:  %{python_module ABCD38 and %python-base >= 3.8}
BuildRequires:  %{python_module XYZ and %python-XYZ2 and NOPY}

> osc build
...
buildinfo is broken... it says:
unresolvable: nothing provides (python36-ABCD36 and python36-base <= 3.6)
      nothing provides (python38-ABCD36 and python38-base <= 3.6)
      nothing provides (python36-ABCD38 and python36-base >= 3.8)
      nothing provides (python38-ABCD38 and python38-base >= 3.8)
      nothing provides (python36-XYZ and python36-XYZ2 and NOPY)
      nothing provides (python38-XYZ and python38-XYZ2 and NOPY)

(In a real world package, replace the and %python-base <= 3.6 with if %python-base <= 3.6)

[bnavigator]

@DimStar77, any thoughts on this? It has to go to the prjconf.

[bnavigator]

#89: Turns out, none of these changes in the python-rpm-macros package have any effect. Only the change in the prjconf does.

[DimStar77]

#89: Turns out, none of these changes in the python-rpm-macros package have any effect. Only the change in the prjconf does.

prjconf does not take you out of the responsibility to provide the proper information also int he rpm: users might want to inspect some logic locally as well.

as for build using OBS / osc 'beating' rpm provided info: it's in ~/.rpmrc, i.e. user confg beats system config.

The config in prjconf MUST be kept at a bare minimum though