Jenkinsfile: use Ubuntu 20.04 for DCO stage
Also switching to use arm64, as all amd64 stages have moved to GitHub actions,
so using arm64 allows the same machine to be used for tests after the DCO check
completed.
@@ -39,7 +39,7 @@ pipeline {
beforeAgent true
expression { params.dco }
}
- agent { label 'amd64 && ubuntu-1804 && overlay2' }
+ agent { label 'arm64 && ubuntu-2004' }
steps {
sh '''
docker run --rm \
