Enable PowerTools repo in %post
This is needed by some EPEL RPMs and potentially some Hyperscale RPMs as well;
flip this on if it is disabled.
We can safely assume this is running on CentOS Stream (there's an explicit
`Requires:` on `centos-stream-release`), and we check that the repo file exists,
and make sure it only contains `_one_` `enabled=` line before modifying.
```
[vagrant@localhost ~]$ dnf repolist enabled
repo id repo name
appstream CentOS Stream 8 - AppStream
baseos CentOS Stream 8 - BaseOS
centos-hyperscale CentOS Stream 8 - Hyperscale
epel Extra Packages for Enterprise Linux 8 - x86_64
epel-modular Extra Packages for Enterprise Linux Modular 8 - x86_64
extras CentOS Stream 8 - Extras
[vagrant@localhost ~]$ sudo dnf install /vagrant/centos-release-hyperscale-4-2.e
l8.noarch.rpm
Last metadata expiration check: 0:03:52 ago on Wed 19 May 2021 11:40:35 PM UTC.
Dependencies resolved.
================================================================================
Package Arch Version Repository Size
================================================================================
Upgrading:
centos-release-hyperscale noarch 4-2.el8 @commandline 9.6 k
Transaction Summary
================================================================================
Upgrade 1 Package
Total size: 9.6 k
Is this ok [y/N]: y
Downloading Packages:
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Upgrading : centos-release-hyperscale-4-2.el8.noarch 1/2
Running scriptlet: centos-release-hyperscale-4-2.el8.noarch 1/2
Cleanup : centos-release-hyperscale-4-1.el8.noarch 2/2
Verifying : centos-release-hyperscale-4-2.el8.noarch 1/2
Verifying : centos-release-hyperscale-4-1.el8.noarch 2/2
Upgraded:
centos-release-hyperscale-4-2.el8.noarch
Complete!
[vagrant@localhost ~]$ dnf repolist enabled
repo id repo name
appstream CentOS Stream 8 - AppStream
baseos CentOS Stream 8 - BaseOS
centos-hyperscale CentOS Stream 8 - Hyperscale
epel Extra Packages for Enterprise Linux 8 - x86_64
epel-modular Extra Packages for Enterprise Linux Modular 8 - x86_64
extras CentOS Stream 8 - Extras
powertools CentOS Stream 8 - PowerTools
```
Signed-off-by: Michel Alexandre Salim <salimma@centosproject.org>