Description of problem:
There were recent changes in rawhide and /usr/bin/yum is not installed by default
but it is still used in anaconda post section to install restraint harness

Version-Release number of selected component (if applicable):
Beaker 26.3 

How reproducible:
Deterministic

Steps to Reproduce:
1. Reserve rawhide machine in beaker
e.g.

<job retention_tag="scratch">
  <whiteboard>fedora rawhide [rs]</whiteboard>
  <recipeSet priority="Normal">
    <recipe whiteboard="" role="RECIPE_MEMBERS" ks_meta="" kernel_options="" kernel_options_post="">
      <autopick random="false"/>
      <watchdog panic="ignore"/>
      <packages/>
      <ks_appends/>
      <repos/>
      <distroRequires>
        <and>
          <distro_family op="=" value="Fedorarawhide"/>
          <distro_variant op="=" value="Server"/>
          <distro_name op="=" value="Fedora-Rawhide-20190331.n.0"/>
          <distro_arch op="=" value="x86_64"/>
        </and>
      </distroRequires>
      <hostRequires>
        <system_type value="Machine"/>
      </hostRequires>
      <partitions/>
      <task name="/distribution/check-install" role="STANDALONE"/>
      <task name="/distribution/reservesys" role="STANDALONE">
        <params>
          <param name="RESERVETIME" value="86400"/>
        </params>
      </task>
    </recipe>
  </recipeSet>
</job>

Actual results:
After some time, machine will be in Aborted state due to timeout waiting for restraint.

Expected results:
Machine reserved without any issue

Additional info:

packaging.log contains:
16:08:37,629 DBG packaging: transaction include list
16:08:37,629 DBG packaging: ['@core', 'chrony', 'kernel', 'grub2-tools', 'chrony', 'firewalld', 'lvm2', 'langpacks-en', 'grub2', 'e2fsprogs', 'xfsprogs']
16:08:37,630 DBG packaging: transaction exclude list
16:08:37,630 DBG packaging: []
16:08:37,665 DBG dnf: No module defaults found
16:08:37,683 Level 8 dnf: Getting group metadata
16:08:37,689 Level 8 dnf: Adding group file from repository: beaker-Fedora-Everything
16:08:37,782 Level 8 dnf: Adding group file from repository: beaker-Fedora
16:08:37,819 Level 8 dnf: Adding group file from repository: anaconda
16:08:37,873 Level 8 dnf: timer: loading comps: 204 ms
16:08:37,979 DBG dnf: Adding packages from group 'core': {<libcomps.Package object 'man-db' at 0x7f1020fd9900>, <libcomps.Package object 'sssd-kcm' at 0x7f1020fd9a68>, <libcomps.Package object 'glibc' at 0x7f1020fd9870>, <libcomps.Package object 'less' at 0x7f1020fd98e8>, <libcomps.Package object 'ncurses' at 0x7f1020fd9918>, <libcomps.Package object 'shadow-utils' at 0x7f1020fd9a38>, <libcomps.Package object 'parted' at 0x7f1020fd9960>, <libcomps.Package object 'lsvpd' at 0x7f1020fd9b40>, <libcomps.Package object 'filesystem' at 0x7f1020fd9858>, <libcomps.Package object 'util-linux' at 0x7f1020fd9ab0>, <libcomps.Package object 'powerpc-utils' at 0x7f1020fd9b58>, <libcomps.Package object 'procps-ng' at 0x7f1020fd99c0>, <libcomps.Package object 'vim-minimal' at 0x7f1020fd9ac8>, <libcomps.Package object 'basesystem' at 0x7f1020fd9420>, <libcomps.Package object 'kbd' at 0x7f1020fd98d0>, <libcomps.Package object 'setup' at 0x7f1020fd9a20>, <libcomps.Package object 'passwd' at 0x7f1020fd9978>, <libcomps.Package object 'policycoreutils' at 0x7f1020fd99a8>, <libcomps.Package object 'e2fsprogs' at 0x7f1020fd9840>, <libcomps.Package object 'openssh-clients' at 0x7f1020fd9930>, <libcomps.Package object 'dnf-yum' at 0x7f1020fd97f8>, <libcomps.Package object 'dhcp-client' at 0x7f1020fd9798>, <libcomps.Package object 'NetworkManager' at 0x7f1020fd9af8>, <libcomps.Package object 'iputils' at 0x7f1020fd98b8>, <libcomps.Package object 'dnf' at 0x7f1020fd9690>, <libcomps.Package object 'iproute' at 0x7f1020fd98a0>, <libcomps.Package object 'rpm' at 0x7f1020fd99f0>, <libcomps.Package object 'plymouth' at 0x7f1020fd9990>, <libcomps.Package object 'rootfiles' at 0x7f1020fd99d8>, <libcomps.Package object 'systemd' at 0x7f1020fd9a98>, <libcomps.Package object 'sudo' at 0x7f1020fd9a80>, <libcomps.Package object 'bash' at 0x7f1020fd9738>, <libcomps.Package object 'sssd-common' at 0x7f1020fd9a50>, <libcomps.Package object 'hostname' at 0x7f1020fd9888>, <libcomps.Package object 'openssh-server' at 0x7f1020fd9948>, <libcomps.Package object 'audit' at 0x7f1020fd9828>, <libcomps.Package object 'dracut-config-rescue' at 0x7f1020fd9b10>, <libcomps.Package object 'coreutils' at 0x7f1020fd9588>, <libcomps.Package object 'curl' at 0x7f1020fd97e0>, <libcomps.Package object 'selinux-policy-targeted' at 0x7f1020fd9a08>, <libcomps.Package object 'firewalld' at 0x7f1020fd9b28>, <libcomps.Package object 'dnf-plugins-core' at 0x7f1020fd9ae0>}
16:08:37,990 WRN dnf: No match for group package "lsvpd"
16:08:37,992 WRN dnf: No match for group package "powerpc-utils"
16:08:37,997 WRN dnf: No match for group package "dnf-yum"
16:08:38,046 Level 8 dnf: timer: depsolve: 40 ms
16:08:38,052 INF packaging: checking dependencies: success
16:08:38,189 DBG packaging: Size from DNF: 878.2 MiB


program.log contains:
16:13:24,813 INF program: + yum check-update
16:13:24,813 INF program: + true
16:13:24,813 INF program: + cat
16:13:24,813 INF program: + cat
16:13:24,813 INF program: + yum -y install restraint-rhts
16:13:24,813 INF program: /tmp/ks-script-9po1bif7: line 208: yum: command not found