Remove rhel7 tree
7.9 has GA's and will be the last release, which means 79-z is the latest release. Since there is no longer a y-stream for rhel7, we should remove rhel7 trees and rename it to 79-z where it's explicitly listed in the test yaml.
7.9 has GA's and will be the last release, which means 79-z is the latest release. Since there is no longer a y-stream for rhel7, we should remove rhel7 trees and rename it to 79-z where it's explicitly listed in the test yaml.