community[patch]: update the default hf bge embeddings (#22627)

**Description:** This updates the langchain_community > huggingface >
default bge embeddings ([the current default recommends this
change](https://huggingface.co/BAAI/bge-large-en))
**Issue:** None
**Dependencies:** None
**Twitter handle:** @jonzeolla

---------

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

libs/community/langchain_community/vectorstores/scann.py

@@ -41,9 +41,10 @@ class ScaNN(VectorStore):
             from langchain_community.embeddings import HuggingFaceEmbeddings
             from langchain_community.vectorstores import ScaNN
 
+            model_name = "sentence-transformers/all-mpnet-base-v2"
             db = ScaNN.from_texts(
                 ['foo', 'bar', 'barz', 'qux'],
-                HuggingFaceEmbeddings())
+                HuggingFaceEmbeddings(model_name=model_name))
             db.similarity_search('foo?', k=1)
     """