Pull Request Labeling does not run automatically for Copilot PRs

[jeffhandley]

Approval by a maintainer is required. Example: https://github.com/dotnet/roslyn/actions/runs/18410427614

[jeffhandley]

Unfortunately, Copilot does not have the required permissions, and because Copilot will create a PR in the main repository rather than in a fork, the permissions canot be granted. If Copilot could create a PR by creating a branch in a fork while submitting the PR into the main repo, the permissions would be there. Copilot is not a maintainer of a fork though, so this isn't available.

The first workaround that comes to mind is to add a workflow that watches for a maintainer to add the default label (needs-area-label in many repos), and have that trigger the labeling, as that workflow would run as the person who took action to apply that label.