langchain

7c2ef061 - Adds "NIN" metadata filter for pgvector to all checking for set absence (#14205)

Adds "NIN" metadata filter for pgvector to all checking for set absence (#14205) This PR adds support for metadata filters of the form: `{"filter": {"key": { "NIN" : ["list", "of", "values"]}}}` "IN" is already supported, so this is a quick & related update to add "NIN"