PYTHON-4817 Revert import guard on asyncio (#1894)

Author: blink1073

pymongo/__init__.py

@@ -88,6 +88,7 @@
 
 from pymongo import _csot
 from pymongo._version import __version__, get_version_string, version_tuple
+from pymongo.asynchronous.mongo_client import AsyncMongoClient
 from pymongo.common import MAX_SUPPORTED_WIRE_VERSION, MIN_SUPPORTED_WIRE_VERSION, has_c
 from pymongo.cursor import CursorType
 from pymongo.operations import (
@@ -104,14 +105,6 @@
 from pymongo.synchronous.mongo_client import MongoClient
 from pymongo.write_concern import WriteConcern
 
-try:
-    from pymongo.asynchronous.mongo_client import AsyncMongoClient
-except Exception as e:
-    # PYTHON-4781: Importing asyncio can fail on Windows.
-    import warnings as _warnings
-
-    _warnings.warn(f"Failed to import Async PyMongo: {e!r}", ImportWarning, stacklevel=2)
-
 version = __version__
 """Current version of PyMongo."""