Recategorize issues with the `Platform` label

Many issues still exist with the Platform label. The Platform team no longer exists.

The transition from Discussion to Plan and Create was easier because the Discussion label was renamed to Plan.

For Platform label the issues need to be manually recategorized. They could now be valid for Create, Manage or another team.

We could create a ~"triage-package" or policy that picks ~Platform issues periodically for recategorization