github PRs: automatically delete branches after merging
diff --git a/.asf.yaml b/.asf.yaml
index 8bb9691..b154e26 100644
--- a/.asf.yaml
+++ b/.asf.yaml
@@ -43,6 +43,7 @@
     merge: false
     squash: true
     rebase: true
+  del_branch_on_merge: true
   features:
     issues: true