langchain

a9457d26 - core: Add async methods to BaseExampleSelector and SemanticSimilarityExampleSelector (#19399)

core: Add async methods to BaseExampleSelector and SemanticSimilarityExampleSelector (#19399) Few-Shot prompt template may use a `SemanticSimilarityExampleSelector` that in turn uses a `VectorStore` that does I/O operations. So to work correctly on the event loop, we need: * async methods for the `VectorStore` (OK) * async methods for the `SemanticSimilarityExampleSelector` (this PR) * async methods for `BasePromptTemplate` and `BaseChatPromptTemplate` (future work)