fix(graph): prevent duplicated append results when merging serial subgraphs#4527

gaozexun wants to merge 2 commits intoalibaba:mainalibaba/spring-ai-alibaba:mainfrom

gaozexun:codex/fix-issue-4515-subgraph-merge-duplication-no-worktreegaozexun/spring-ai-alibaba:codex/fix-issue-4515-subgraph-merge-duplication-no-worktreeCopy head branch name to clipboard