Temporarly increase automerge timeout due to #10169 increase jekyll build time (#10591)

Signed-off-by: Peter Zhu <[email protected]>
(cherry picked from commit f6cd2fd)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

.github/workflows/automerge-backport.yml

@@ -25,8 +25,8 @@ jobs:
           MERGE_LABELS: "backport-automerge,!On hold"
           MERGE_FILTER_AUTHOR: "opensearch-trigger-bot[bot]"
           MERGE_REQUIRED_APPROVALS: "1"
-          MERGE_RETRIES: "30"
-          MERGE_RETRY_SLEEP: "10000"
+          MERGE_RETRIES: "50"
+          MERGE_RETRY_SLEEP: "20000"
           MERGE_ERROR_FAIL: "true"
           MERGE_FORKS: "false"
           MERGE_METHOD: "squash"