Enable draft builds in CBS

Issue Type

• [] Issue - problem with something that was working
• Feature Request - something you'd like us to add/modify/change
• [] Task - mostly used by CentOS Infra team for day-to-day operations or bigger plans

Description

As discussed at CentOS Connect, the Hyperscale SIG would like to experiment with draft builds as part of our CI flows, and we'd like to request the feature to be enabled in CBS.