Reusable workflows can now be called from a matrix and other reusable workflows.

### Prerequisites

- [X] I have written a descriptive issue title
- [X] I have searched existing issues to ensure the issue has not already been raised


### Issue

Since yesterday: 
https://github.blog/changelog/2022-08-22-github-actions-improvements-to-reusable-workflows-2/

We could now put the redundant parts from the plugins-ci*.yml files in other workflows and call the reusable workflows.