[border-agent] fix struct typedef for otBorderAgentId (#9277)

include/openthread/border_agent.h

@@ -69,6 +69,12 @@ struct otBorderAgentId
     uint8_t mId[OT_BORDER_AGENT_ID_LENGTH];
 } OT_TOOL_PACKED_END;
 
+/**
+ * Represents a Border Agent ID.
+ *
+ */
+typedef struct otBorderAgentId otBorderAgentId;
+
 /**
  * Defines the Border Agent state.
  *

include/openthread/instance.h

@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (343)
+#define OPENTHREAD_API_VERSION (344)
 
 /**
  * @addtogroup api-instance