Release 9.6 - protect the release branch (#2418)

diff --git a/.asf.yaml b/.asf.yaml
index 6e91bf6..602feeb 100644
--- a/.asf.yaml
+++ b/.asf.yaml
@@ -27,6 +27,7 @@
     branch_9_3: {}
     branch_9_4: {}
     branch_9_5: {}
+    branch_9_6: {}
     branch_9x: {}
 
   protected_tags: