[minor] Deep Lake auth improvements in docs, kwargs pass, faster tests (#2927)

Minor cosmetic changes 
- Activeloop environment cred authentication in notebooks with
`getpass.getpass` (instead of CLI which not always works)
- much faster tests with Deep Lake pytest mode on 
- Deep Lake kwargs pass

Notes
- I put pytest environment creds inside `vectorstores/conftest.py`, but
feel free to suggest a better location. For context, if I put in
`test_deeplake.py`, `ruff` doesn't let me to set them before import
deeplake

---------

Co-authored-by: Davit Buniatyan <d@activeloop.ai>

tests/integration_tests/vectorstores/conftest.py

@@ -9,6 +9,13 @@ from langchain.embeddings import OpenAIEmbeddings
 from langchain.schema import Document
 from langchain.text_splitter import CharacterTextSplitter
 
+# Those environment variables turn on Deep Lake pytest mode.
+# It significantly makes tests run much faster.
+# Need to run before `import deeplake`
+os.environ["BUGGER_OFF"] = "true"
+os.environ["DEEPLAKE_DOWNLOAD_PATH"] = "./testing/local_storage"
+os.environ["DEEPLAKE_PYTEST_ENABLED"] = "true"
+
 
 # This fixture returns a dictionary containing filter_headers options
 # for replacing certain headers with dummy values during cassette playback