Changes to List meeting sessions

the provider response property const value changed from anam to telnyx for the status 200

added the required property data/items/avatar/oneOf[subschema #1: MeetingSessionAvatar]/background_id to the response with the 200 status

added the required property data/items/avatar/oneOf[subschema #1: MeetingSessionAvatar]/model to the response with the 200 status

added the new full_duplex enum value to the data/items/assistant/oneOf[subschema #1: MeetingSessionAssistant]/audio_gate response property for the response status 200

removed the none enum value from the data/items/assistant/oneOf[subschema #1: MeetingSessionAssistant]/audio_gate response property for the response status 200

added the required property data/items/assistant/oneOf[subschema #1: MeetingSessionAssistant]/dynamic_variables to the response with the 200 status

added the required property data/items/assistant/oneOf[subschema #1: MeetingSessionAssistant]/leave_on_end to the response with the 200 status

added the required property data/items/config/chat_on_enter to the response with the 200 status

endpoint added