refactor: remove unused legacy parameters from __init__

- Addresses review feedback from @davidsbatista
- Removed: sql_url, faiss_index_factory_str, similarity, isolation_level, duplicate_documents, return_embedding, progress_bar
- Updated docstrings

Author: GunaPalanivel

integrations/faiss/src/haystack_integrations/document_stores/faiss/document_store.py

@@ -25,16 +25,9 @@ class FAISSDocumentStore:
 
     def __init__(
         self,
-        sql_url: str = "sqlite:///:memory:",  # Kept for compatibility but unused
         index_path: str | None = None,
         index_string: str = "Flat",
         embedding_dim: int = 768,
-        faiss_index_factory_str: str | None = None,  # Legacy parameter support
-        similarity: str = "dot_product",  # Legacy parameter
-        isolation_level: str | None = None,  # Legacy parameter
-        duplicate_documents: str = "overwrite",  # Legacy parameter
-        return_embedding: bool = True,
-        progress_bar: bool = True,  # Legacy parameter
     ):
         """
         Initializes the FAISSDocumentStore.