Adding deprectaion message and removing an experimental test (#1977)

libraries/botbuilder-schema/botbuilder/schema/__init__.py

@@ -1,6 +1,8 @@
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License.
 
+from warnings import warn
+
 from ._models_py3 import Activity
 from ._models_py3 import ActivityEventNames
 from ._models_py3 import AdaptiveCardInvokeAction
@@ -75,6 +77,10 @@
 from .callerid_constants import CallerIdConstants
 from .speech_constants import SpeechConstants
 
+warn(
+    "The Bot Framework Python SDK is being retired with final long-term support ending in November 2023, after which this repository will be archived. There will be no further feature development, with only critical security and bug fixes within this repository being undertaken. Existing bots built with this SDK will continue to function. For all new bot development we recommend that you adopt Power Virtual Agents."
+)
+
 __all__ = [
     "Activity",
     "ActivityEventNames",