lorax-templates-rhel conditional check applied too broadly

[MoralCode]

f447421 from #489 implemented a check to ensure that the lorax-templates-rhel package is only included in the anaconda iso builds for distros that ship it. According to the commit message, the distros that have this are "EL-like distros and Fedora ELN".

However the check that was actually implemented reads c.SourceInfo.OSRelease.ID != "fedora" || c.SourceInfo.OSRelease.VersionID == "eln", which has the (presumably) unintended side effect of trying to include this EL-only package in ISO builds for any image that wants to be based on non-eln fedora, but have its own ID in /etc/os-release.

Until there is some way to collectively identify EL and EL-based distros (maybe via ID_LIKE=centos or something as discussed in similar issue #690), It would be nice to relax this if condition so the community can have an easier time building their own custom bootc images based on Fedora non-ELN