Trigger dev deployment script is triggered for any push, not only on dev

[FelixKirsch]

Describe the bug The dev deployment script is called on a push to any branch. This is unnecessary, it needs only to be called when pushing to the dev branch.

To Reproduce Push to a branch in any refinery-repo. In each drone.yml, it is defined that the "trigger update" task is executed on push to any branch.

Fix The fix is easy but takes some time because the drone.yml file has to be changed in every refinery-repo. The trigger update task has to be separated in its own pipeline which depends on the existing pipeline. But in addition, this new pipeline is only triggered if anything is pushed to "dev" and not for any other branch.