Move zuul jobs layout to centos9 only for master branch
Move zuul jobs layout to centos9 only for master branch

See topic branch [1] for related reviews.

[1] https://review.opendev.org/q/topic:c8_teardown_master
Depends-On: https://review.opendev.org/c/openstack/tripleo-ci/+/826317

Change-Id: I2e8174d3c4df4165c3420a31785cb280e4065c17

openstack/puppet-tripleo,openstack/puppet-tripleo,openstack/puppet-tripleo