Fix recover log stack attr format

Signed-off-by: Émile Ré <nemile.re@gmail.com>

pkg/server/gqlutils/recovery.go

@@ -83,7 +83,7 @@ func RecoverFunc(ctx context.Context, err any) error {
 	}
 
 	logger := httpserver.LoggerFromContext(ctx)
-	logger.Error("resolver panic", log.Any("error", err), log.Any("stack", string(debug.Stack())))
+	logger.Error("resolver panic", log.Any("error", err), log.String("stack", string(debug.Stack())))
 
 	return errors.New("internal server error")
 }