chore(.asf.yaml): add 2.16 into protected branches (#3535)

PragmaTwice · web-flow · commit b0ae44fe7c8c · 2026-06-22T08:59:01.000+08:00
We can add `2.16` to protected branches since it's released now.
diff --git a/.asf.yaml b/.asf.yaml
@@ -68,6 +68,7 @@ github:
     '2.13': {}
     '2.14': {}
     '2.15': {}
+    '2.16': {}
 
 notifications:
   commits:      commits@kvrocks.apache.org
