Trigger "On single new message from queue session" does not process next session message until session lock expiry

### Describe the Bug

The built-in Logic Apps Standard Service Bus session trigger "On single new message from queue session" appears to lock the accepted queue session after the workflow has completed and explicitly completed the message.

Because the trigger emits only one message per run and does not continue draining the session, subsequent messages for the same SessionId are not delivered until the session lock expires unless the workflow explicitly calls Close queue session.

### Plan Type

Standard

### Steps to Reproduce the Bug or Issue

1. Session lock duration set to: 5 minutes
2. Workflow using trigger "On single new message from queue session" followed by Close message.
3. In the service bus queue up 50 or more messages using half a dozen different session IDs.
4. Enable the consumer workflow.
5. Observed behaviour: messages processed in bursts every ~5 minutes
6. After adding Close queue session after Complete: all messages processed in <20 seconds

### Expected Result

The workflow should process the remaining messages in the queue matching the session ID of the session its trigger currently holds without waiting for the lock duration to expire or having to close the session.

Reproduce the behavior with a Standard Logic Apps workflow using the “On single new message from queue session” trigger, Complete message, and Close queue session, then compare processing with and without closing the session. Verify that remaining messages for the held SessionId are delivered without waiting for session-lock expiry or requiring an explicit close.

Written by the indexing model from the issue text.