dev/dn: allow 'service/...' labels to specify when to get notified
Created by: bobheadxi
If I deploy a change to a particular service, I'd like to be able to only get notified when my change is deployed for that service (i.e. if I bump Prometheus, I do not want to know when frontend etc gets rolled out)
To enable this, add a check for labels service/...
and only notify if the set of changed services includes the specified labels. If no such labels are specified, notify on all deployments
For example: https://github.com/sourcegraph/sourcegraph/pull/33927
Test plan
n/a