Update mock configs

[ekohl]

This uses the mock configs from the host to reduce duplication. It also uses modularity in EL8 rather than using a flattened layout.

Additionally an EL9 mock config is created.

Right now this is a draft since I can't get rpmbuild to work locally. Ideally obal would also use mock to build SRPMs.

[ehelms]

This seems to work right nice:

TASK [build_srpm : Built srpm path] ******************************************************************************************************************************************************************************************************************************************************
ok: [python-packaging] => 
  msg: Built /home/ehelms/workspace/upstream/packaging/pulpcore-packaging/SRPMs/tfm-pulpcore-python-packaging-21.3-1.src.rpm

PLAY [packages] **************************************************************************************************************************************************************************************************************************************************************************
^[[1;5B
TASK [Build with mock] *******************************************************************************************************************************************************************************************************************************************************************
ok: [python-packaging]

PLAY RECAP *******************************************************************************************************************************************************************************************************************************************************************************
python-packaging           : ok=20   changed=3    unreachable=0    failed=0    skipped=1    rescued=0    ignored=1   

Any objection to taking it out of draft mode and we merge it?

[ekohl]

@ehelms taken out of draft.

[ekohl]

#586 is the same for 3.21.