Trigger DRA snapshots for 9.x branches as well

Author: mark-vieira

.buildkite/pipelines/intake.template.yml

@@ -96,7 +96,7 @@ steps:
   - trigger: elasticsearch-dra-workflow
     label: Trigger DRA snapshot workflow
     async: true
-    branches: "main 8.* 7.17"
+    branches: "main 9.* 8.* 7.17"
     build:
       branch: "$BUILDKITE_BRANCH"
       commit: "$BUILDKITE_COMMIT"