Fix missing docker staging DRA artifacts (#39297)

The DRA staging release is failing because the Buildkite step isn't capturing the right artifacts.
This commit fixes the issue by adjusting the artifact_paths to match the other steps.

.buildkite/packaging.pipeline.yml

@@ -179,7 +179,7 @@ steps:
           imagePrefix: "${AWS_IMAGE_UBUNTU_ARM_64}"
           instanceType: "${AWS_ARM_INSTANCE_TYPE}"
         artifact_paths:
-          - build/distributions/**
+          - build/distributions/**/*
         matrix:
           - auditbeat
           - filebeat