Story

In the Overlay repository, the number of opened PRs can be rather high, and among the automatically-created PRs, we want to be able to quickly identify the subset of PRs related to mandatory workspaces, that should be looked into and merged before the next release branch is created.

Implementation

There are mainly 2 options here:

1. integrate this into the discovery workspace (Update plugins repository references). The problem with this option is that labels will not be applied to already-existing PRs, and labels would not be added after-the-facts when new workspaces are added to the list of mandatory workspaces.
2. Create a dedicated scheduled daily workflow which goes through all the PRs and checks the workspace it relates to and adds or removes the label.  

Implementation 2 is favored.

Background

Mandatory workspaces are workspaces which should be part of a release branch, since they contain at least one productized plugin.