When creating a new workflow on your repository, you will see templates originating from here. https://github.com/nextcloud/viewer/actions/new
For each template, you can propagate them on all the repos that use it.
- Go into https://github.com/nextcloud/.github/actions/workflows/dispatch-workflow.yml
- Enter the name of the workflow you want to dispatch
- Enter the page you want to execute (100 are done per page, so check the number of repositories, current is 260 so run for page: 1, 2 and 3)
- Wait for the actions to finish and see the checkout the pull requests