munin: avoid using a template for debci_packages_processed

Rather than figure out the workers at deployment time, we can defer that to runtime by using a unit pattern and thus avoid the need for a template.

Ha, this means that in the past when I was playing with the number of debci-workers, the packages processed by them have been missed in the graphs. That might have influenced the current numbers.

mentioned in merge request freexian-team/ansible/debian-infrastructure!6 (merged)

merged

mentioned in commit 24458ea9