#1189 Jenkinsfile: temporarily disable Develocity.
The Eclipse Foundation storage cluster outage issues are ongoing (see #1189 (closed)). Our Jenkins CI is up and running again. But, Develocity is still down, so our builds fail. This temporarily disables Develocity in our Jenkinsfile. It should be back in 1-2 weeks, hopefully, and then we can undo these changes.
Addresses #1189 (closed)