Remove the node attribute as these can run on any node. I've configured
the three deb11 nodes with "Usage: Use this node as much as possible"
instead of previously "Only build jobs with label expression matching
this node", so simply not specifying a node is now possible. Previously
it wouldn't have any node to run on as all of them were configured that
way.
Related: OS#5793
Change-Id: I2d67daf1cc7930649d097af23c18990cc3ae55fd
Trigger registry-rebuild-upload-titan on changes in
osmo-ttcn3-hacks.git. Write registry-triggers.yml with a job template,
so we could add more triggers from git repos -> registry easily if
needed in the future.
Related: OS#5017
Change-Id: Ib6a27be6351ce821c7023a1f75a82b1ade2ffa49