Add missing filter to max_marginal_relevance_search inner call to max_marginal_relevance_search_by_vector (#13260)

When calling max_marginal_relevance_search from PGVector the filter
param is not carried over to max_marginal_relevance_search_by_vector

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/langchain/langchain/vectorstores/pgvector.py

@@ -762,6 +762,7 @@ class PGVector(VectorStore):
             k=k,
             fetch_k=fetch_k,
             lambda_mult=lambda_mult,
+            filter=filter,
             **kwargs,
         )