fix(client): avoid private import of Langfuse to satisify Pyright (#1275)

Co-authored-by: Hassieb Pakzad <68423100+hassiebp@users.noreply.github.com>

Author: janwinkler1

langfuse/__init__.py

@@ -1,11 +1,13 @@
 """.. include:: ../README.md"""
 
 from ._client.attributes import LangfuseOtelSpanAttributes
-from ._client.client import Langfuse
 from ._client.get_client import get_client
+from ._client import client as _client
 from ._client.observe import observe
 from ._client.span import LangfuseEvent, LangfuseGeneration, LangfuseSpan
 
+Langfuse = _client.Langfuse
+
 __all__ = [
     "Langfuse",
     "get_client",