feat(loader): enhance single active backend by treating as singleton (#5107)

feat(loader): enhance single active backend by treating at singleton

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

core/backend/vad.go

@@ -19,6 +19,8 @@ func VAD(request *schema.VADRequest,
 	if err != nil {
 		return nil, err
 	}
+	defer ml.Close()
+
 	req := proto.VADRequest{
 		Audio: request.Audio,
 	}