Handle the conflicts between base module modular Koji tags everytime.
Currently, we generate `Conflicts` for ursine RPMs conflicting with
modular RPMs only when Ursa Prime is used for the base module. This
commit changes it, so these Conflicts are generated everytime.
The reason is that modular RPMs should always be preferred in the
buildroot over the ursine RPMs no matter what is their NVR. So far,
this has been guarded on Koji side by using external repos, but
we need to move away from external repo or at least use "bare"
merge mode which basically means we won't get this feature for free
from Koji.
The reason why we need to move away from external repos or use "bare"
merge mode is that without this, the Koji removes RPMs sharing the same
name but different version/release from the buildroot and only keeps
the latest one. This is an issue in situation when you need two
versions of single RPM in a buildroot comming from two modules.