Python: fix for enum handling in openai event creation in realtime (#11397)

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Fix for how the openai realtime event type constructors deal with enums,
fixes #11246

### Description

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- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [SK Contribution
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Author: eavanvalkenburg

python/semantic_kernel/connectors/ai/open_ai/services/_open_ai_realtime.py

@@ -151,51 +151,53 @@ class SendEvents(str, Enum):
     RESPONSE_CANCEL = "response.cancel"
 
 
-def _create_openai_realtime_client_event(event_type: SendEvents, **kwargs: Any) -> RealtimeClientEvent:
+def _create_openai_realtime_client_event(event_type: SendEvents | str, **kwargs: Any) -> RealtimeClientEvent:
     """Create an OpenAI Realtime client event from a event type and kwargs."""
+    if isinstance(event_type, str):
+        event_type = SendEvents(event_type)
     match event_type:
         case SendEvents.SESSION_UPDATE:
             if "session" not in kwargs:
                 raise ContentException("Session is required for SessionUpdateEvent")
             return SessionUpdateEvent(
-                type=event_type,
+                type=event_type.value,
                 session=kwargs.pop("session"),
                 **kwargs,
             )
         case SendEvents.INPUT_AUDIO_BUFFER_APPEND:
             if "audio" not in kwargs:
                 raise ContentException("Audio is required for InputAudioBufferAppendEvent")
             return InputAudioBufferAppendEvent(
-                type=event_type,
+                type=event_type.value,
                 **kwargs,
             )
         case SendEvents.INPUT_AUDIO_BUFFER_COMMIT:
             return InputAudioBufferCommitEvent(
-                type=event_type,
+                type=event_type.value,
                 **kwargs,
             )
         case SendEvents.INPUT_AUDIO_BUFFER_CLEAR:
             return InputAudioBufferClearEvent(
-                type=event_type,
+                type=event_type.value,
                 **kwargs,
             )
         case SendEvents.CONVERSATION_ITEM_CREATE:
             if "item" not in kwargs:
                 raise ContentException("Item is required for ConversationItemCreateEvent")
-            kwargs["type"] = event_type
+            kwargs["type"] = event_type.value
             return ConversationItemCreateEvent(**kwargs)
         case SendEvents.CONVERSATION_ITEM_TRUNCATE:
             if "content_index" not in kwargs:
                 kwargs["content_index"] = 0
             return ConversationItemTruncateEvent(
-                type=event_type,
+                type=event_type.value,
                 **kwargs,
             )
         case SendEvents.CONVERSATION_ITEM_DELETE:
             if "item_id" not in kwargs:
                 raise ContentException("Item ID is required for ConversationItemDeleteEvent")
             return ConversationItemDeleteEvent(
-                type=event_type,
+                type=event_type.value,
                 **kwargs,
             )
         case SendEvents.RESPONSE_CREATE:
@@ -204,13 +206,13 @@ def _create_openai_realtime_client_event(event_type: SendEvents, **kwargs: Any)
             else:
                 response = None
             return ResponseCreateEvent(
-                type=event_type,
+                type=event_type.value,
                 response=response,
                 **kwargs,
             )
         case SendEvents.RESPONSE_CANCEL:
             return ResponseCancelEvent(
-                type=event_type,
+                type=event_type.value,
                 **kwargs,
             )