ci: PR number 비교 처리 변경

Author: bky373

.github/workflows/automation.yaml

@@ -37,10 +37,10 @@ jobs:
 
           # 최근 3개의 PR 중 현재 PR 작성자와 다른 작성자 찾기
           previous_pr_author=$(gh pr list --repo $current_repo \
-            --search "number:<$current_pr_num -is:closed sort:created-desc -author:$current_pr_author" \
-            --limit 3 --json author \
-            --jq '.[0].author.login')
-
+            --search "-is:closed sort:created-desc -author:$current_pr_author" \
+            --limit 3 --json number,author \
+            --jq 'map(select(.number < '$current_pr_num'))[0].author.login')
+          
           if [ -n "$previous_pr_author" ]; then
             gh pr edit $current_pr_num --repo $current_repo --add-reviewer $previous_pr_author
           else