[REM] remove the Memo component

With the new fine grained reactivity system, it was no longer useful.

src/index.ts

@@ -42,7 +42,6 @@ export { App, mount } from "./app/app";
 export { Component } from "./component/component";
 export { useComponent, useState } from "./component/component_node";
 export { status } from "./component/status";
-export { Memo } from "./memo";
 export { xml } from "./app/template_set";
 export { reactive, markRaw, toRaw } from "./reactivity";
 export { useEffect, useEnv, useExternalListener, useRef, useChildSubEnv, useSubEnv } from "./hooks";