Suppress warnings in interactive env that stem from tab completion (#11190)

Suppress warnings in interactive environments that can arise from users 
relying on tab completion (without even using deprecated modules).

jupyter seems to filter warnings by default (at least for me), but
ipython surfaces them all

libs/langchain/langchain/__init__.py

@@ -20,7 +20,21 @@ debug: bool = False
 llm_cache: Optional["BaseCache"] = None
 
 
+def _is_interactive_env() -> bool:
+    """Determine if running within IPython or Jupyter."""
+    import sys
+
+    return hasattr(sys, "ps2")
+
+
 def _warn_on_import(name: str) -> None:
+    """Warn on import of deprecated module."""
+    if _is_interactive_env():
+        # No warnings for interactive environments.
+        # This is done to avoid polluting the output of interactive environments
+        # where users rely on auto-complete and may trigger this warning
+        # even if they are not using any deprecated modules
+        return
     warnings.warn(
         f"Importing {name} from langchain root module is no longer supported."
     )