remove `dnsmasq` from the default package set

[miabbott]

We saw a report in the RHEL for Edge downstream about how the inclusion of dnsmasq in the OS was causing issues for CIS Level 1 server compliance. (Example audit rule for CIS compliance - https://www.tenable.com/audits/items/CIS_Oracle_Linux_9_v2.0.0_L1_Server.audit:35758e8a3ea48aff90e79b2d49199741)

The git archeology for the inclusion of that package appears to go back to the first definition of the IoT package set - https://pagure.io/fedora-iot/ostree/c/e4dff0e6fb85568963701ced7e8ca97e88e5f74a?branch=master

This looks very similar to the base content set that was used for Fedora Atomic Host and the rationale for the inclusion of dnsmasq in Atomic Host had to do with supporting openshift-ansible/OpenShift 3.11 - https://www.pagure.io/fedora-atomic/c/0435250a9308ba55e56f3c31edfe63aab2c41d8d

An inspection of the Requires/Recommends on dnsmasq doesn't show any default packages that depend on the package:

[core@localhost ~]$ rpm -q --whatrequires dnsmasq
no package requires dnsmasq
[core@localhost ~]$ rpm -q --whatrecommends dnsmasq
no package recommends dnsmasq

Given the history and lack of dependencies on the package, it seems like a good candidate for removal from IoT.

(We already decided to remove it from future versions of RHEL for Edge - https://github.com/osbuild/images/pull/921)

[nullr0ute]

Yes, makes sense, from (a very vague) memory it was originally needed for container networking, but that's no longer the case. Filed this PR: https://pagure.io/fedora-iot/ostree/pull-request/62

[pcdubs]

Merged.