From T221872, I got rid of the Docker workers that had just 2GB RAM. That also means that the `m4executor` label is no more needed since all Docker workers are similar now. There are probably a few labels that are no more needed, so this task about listing all labels and find out what they are for/whether we can delete them.
https://integration.wikimedia.org/ci/computer/
All labels:
`contint1001:~$ (cd /var/lib/jenkins/nodes && grep -i '<label>' */config.xml)|sed -e 's/\(^\|:\)/|/g'`
|compiler1001.puppet-diffs.eqiad.wmflabs/config.xml| <label>puppet-compiler-node</label>
|compiler1002.puppet-diffs.eqiad.wmflabs/config.xml| <label>puppet-compiler-node</label>
|compiler1003.puppet-diffs.eqiad.wmflabs/config.xml| <label>puppet-compiler-node</label>
|contint1001/config.xml| <label>productionAgents blubber dockerPublish train</label>
|deployment-deploy01/config.xml| <label>BetaClusterBastion</label>
|integration-agent-docker-1001/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1002/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1003/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1004/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1005/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1006/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1007/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1008/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1009/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1010/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1011/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1012/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1013/config.xml| <label>Docker blubber</label>
|integration-agent-docker-1014/config.xml| <label>codehealth</label>
|integration-agent-docker-1016/config.xml| <label>Docker blubber</label>
|integration-agent-jessie-docker-1001/config.xml| <label>Docker blubber</label>
|integration-agent-pkgbuilder-1001/config.xml| <label>DebianGlue</label>
|integration-agent-pkgbuilder-1002/config.xml| <label>DebianGlue</label>
|integration-agent-puppet-docker-1001/config.xml| <label>puppet</label>
|integration-castor03/config.xml| <label></label>
|integration-slave-jessie-1002/config.xml| <label>DebianJessie contintLabsSlave</label>
|integration-slave-jessie-1004/config.xml| <label>DebianJessie contintLabsSlave</label>
|integration-trigger-01/config.xml| <label>trigger</label>
|saucelabs-01/config.xml| <label>BrowserTests</label>
|saucelabs-02/config.xml| <label>BrowserTests</label>