Update release for aarch64

Switch to %posttrans for enabling powertools;
transaction
Limit it to the hotfixes subpackage as that requires EPEL

Trigger enabling powertools repo on package installations and upgrades
Fix license declaration; match centos-stream-repos

Add subpackages for hotfixes and spin repo configs
Require epel-release for hotfixes
Preserve timestamps on installs

Drop obsoletes for centos-hyperscale-keys as it was never actually built

Bring the keys back in and obsolete centos-hyperscale-keys
Bring centos-release-hyperscale-experimental in as a subpackage

Factor out keys in centos-hyperscale-keys and require it

Require centos-stream-release instead of centos-release

Initial release