doc: fix wrong documentation on FAISS load_local function (#22310)

### Issue: #22299 

### descriptions
The documentation appears to be wrong. When the user actually sets this
parameter "asynchronous" to be True, it fails because the __init__
function of FAISS class doesn't allow this parameter. In fact, most of
the class/instance functions of this class have both the sync/async
version, so it looks like what we need is just to remove this parameter
from the doc.

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Co-authored-by: Lifu Wu <lifu@nextbillion.ai>

libs/community/langchain_community/vectorstores/faiss.py

@@ -1072,7 +1072,6 @@ class FAISS(VectorStore):
                 Pickle files can be modified by malicious actors to deliver a
                 malicious payload that results in execution of
                 arbitrary code on your machine.
-            asynchronous: whether to use async version or not
         """
         if not allow_dangerous_deserialization:
             raise ValueError(