Update yum config for CentOS Stream 9

[pdohertybcov]

Description

The Powertools repo doesn't exist for CentOS Stream 9. The equivalent packages are in the CRB repo. This adds a second conditional statement to enable the CRB repo if the platform_version is 9 and changes the conditional for the powertools repo from >= 8 to == 8

When trying to use this cookbook on CentOS Stream 9 is resulted in an error like below:

         * ruby_build_install[] action install
           * dnf_package[yum-utils] action install (up to date)
           * execute[yum-config-manager --enable powertools] action run

             ================================================================================
             Error executing action `run` on resource 'execute[yum-config-manager --enable powertools]'
             ================================================================================

             Mixlib::ShellOut::ShellCommandFailed
             ------------------------------------
             Expected process to exit with [0], but received '1'
             ---- Begin output of yum-config-manager --enable powertools ----
             STDOUT:
             STDERR: Error: No matching repo to modify: powertools.
             ---- End output of yum-config-manager --enable powertools ----
             Ran yum-config-manager --enable powertools returned 1

             Cookbook Trace: (most recent call first)
             ----------------------------------------
             /tmp/kitchen/cache/cookbooks/ruby_build/resources/install.rb:16:in `block in class_from_file'

             Resource Declaration:
             ---------------------
             # In /tmp/kitchen/cache/cookbooks/ruby_build/resources/install.rb

       16:       execute 'yum-config-manager --enable powertools' do
       17:         not_if 'yum-config-manager --dump powertools | grep -q "enabled = 1"'
       18:       end
       19:     end

Issues Resolved

List any existing issues this PR resolves

Check List

• A summary of changes made is included in the CHANGELOG under ## Unreleased
• New functionality includes testing.
• New functionality has been documented in the README if applicable.

[damacus]

Excellent thank you for this!

[kitchen-porter]

Released as: 2.5.6