Add a label condition on the project assignment reusable workflow

[LaRiffle]

Problem

We have created a nice workflow for auto assignment to GH projects of issues of dedicated repos, but for HDS we'd like a generic instantiation that tracks in the Incident Project all issues from all Arkhn repos which have the type/incident label

Implementation

• Add an optional variable to https://github.com/arkhn/.github/blob/main/.github/workflows/project.yml
• filter on that var when provided
• Add a workflow directly in this repo that call that re-usable workflow