refactor(langchain): clean redundancy ifelse.

[湛露先生 (zhanluxianshen)]

Fixes #

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[codspeed-hq]

Merging this PR will not alter performance

✅ 2 untouched benchmarks
⏩ 13 skipped benchmarks¹

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_{Comparing zhanluxianshen:redundancy-ifelse (22f482b) with master (f42d80c)²}

Footnotes

1. 13 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

2. No successful run was found on master (0831e44) during the generation of this report, so f42d80c was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩