ossf security best practice: The project MUST have evidence that the [test_policy](https://www.bestpractices.dev/en/projects/11652/passing/edit#test_policy) for adding tests has been adhered to in the most recent major changes to the software produced by the project

- [ ] Add CI check to see if tests are included
- [ ] headlamp frontend
- [ ] headlamp backend
- [ ] plugins

Check the test coverage does not go down VS main branch.
Note: see backend / frontend old CI jobs in headlamp repo for inspo.
Note: commenting does not work because of security restrictions blocking a forks CI runs from posting comments

Start by reviewing the old backend and frontend CI jobs in the Headlamp repository, as suggested in the issue. Define the CI checks for headlamp frontend, headlamp backend, and plugins; done means tests are included and test coverage does not decrease compared with the main branch, without relying on fork comments.

Written by the indexing model from the issue text.