fix: metadata serialization in AstraDB vector store (#8855)

* fix(astradb): serialize metadata in documents

* chore: update starter projects

* [autofix.ci] apply automated fixes

* [autofix.ci] apply automated fixes (attempt 2/3)

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Eric Hare <ericrhare@gmail.com>

src/backend/base/langflow/components/vectorstores/astradb.py

@@ -7,6 +7,7 @@ from astrapy.data.info.reranking import RerankServiceOptions
 from astrapy.info import CollectionDescriptor, CollectionLexicalOptions, CollectionRerankOptions
 from langchain_astradb import AstraDBVectorStore, VectorServiceOptions
 from langchain_astradb.utils.astradb import HybridSearchMode, _AstraDBCollectionEnvironment
+from langchain_core.documents import Document
 
 from langflow.base.vectorstores.model import LCVectorStoreComponent, check_cached_vector_store
 from langflow.base.vectorstores.vector_store_connection_decorator import vector_store_connection
@@ -22,6 +23,7 @@ from langflow.io import (
     StrInput,
 )
 from langflow.schema.data import Data
+from langflow.serialization import serialize
 from langflow.utils.version import get_version_info
 
 
@@ -1164,6 +1166,10 @@ class AstraDBVectorStoreComponent(LCVectorStoreComponent):
                 msg = "Vector Store Inputs must be Data objects."
                 raise TypeError(msg)
 
+        documents = [
+            Document(page_content=doc.page_content, metadata=serialize(doc.metadata, to_str=True)) for doc in documents
+        ]
+
         if documents and self.deletion_field:
             self.log(f"Deleting documents where {self.deletion_field}")
             try: