[ImgBot] Optimize images

*Total -- 608.90kb -> 585.60kb (3.83%)

/svgs/langchain-parent-document-retriever.svg -- 86.66kb -> 82.40kb (4.91%)
/svgs/langchain-modules.svg -- 147.84kb -> 140.70kb (4.83%)
/svgs/langchain-js-auto-docstrings.svg -- 99.27kb -> 95.23kb (4.07%)
/svgs/langchain-use-cases.svg -- 132.22kb -> 128.27kb (2.99%)
/svgs/langchain-js-runnable-chain.svg -- 142.91kb -> 139.00kb (2.74%)

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