Enable Buildkite DRA workflows and delete Jenkins ones (elastic#100213)

(cherry picked from commit 1a969c3)

Author: brianseeders

.buildkite/scripts/dra-workflow.sh

@@ -71,8 +71,6 @@ find "$WORKSPACE" -type d -path "*/build/distributions" -exec chmod a+w {} \;
 
 echo --- Running release-manager
 
-exit 0
-
 # Artifacts should be generated
 docker run --rm \
   --name release-manager \