Fix: IPA image buidling with OpenSuse.
Fix: IPA image buidling with OpenSuse.

At this moment the IPA image building with OpenSuse is broken and here, it was failing during the release check for Opensue because etc/SuSE-release is not valid anymore and deprecated for openSuse. Its renamed to /etc/os-release for openSuse rlease 15. This PR will solve the issue to build IPA image with OpenSuse base image. There is another PR opened in ironic-python-agent-builder, which adds all the missing packages, setuptools upgrade and svc mapping to do the build successful.
https://review.opendev.org/c/openstack/ironic-python-agent-builder/+/778726

Bug-Report: https://bugs.launchpad.net/diskimage-builder/+bug/1921510

Change-Id: Id2759be29bfcbf2ecf1ce67e171686924b506b1a

openstack/diskimage-builder,openstack/diskimage-builder