Fix documentation typo in Clickhouse Class (#12047)

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- **Description:** The return info in the documentation for
similarity_search_by_vector and similarity_search_with_relevance_scores
is wrong

libs/langchain/langchain/vectorstores/clickhouse.py

@@ -410,7 +410,7 @@ CREATE TABLE IF NOT EXISTS {self.config.database}.{self.config.table}(
                   alone. The default name for it is `metadata`.
 
         Returns:
-            List[Document]: List of (Document, similarity)
+            List[Document]: List of documents
         """
         q_str = self._build_query_sql(embedding, k, where_str)
         try:
@@ -442,7 +442,7 @@ CREATE TABLE IF NOT EXISTS {self.config.database}.{self.config.table}(
                   alone. The default name for it is `metadata`.
 
         Returns:
-            List[Document]: List of documents
+            List[Document]: List of (Document, similarity)
         """
         q_str = self._build_query_sql(
             self.embedding_function.embed_query(query), k, where_str