chore: remove dead code (#8472)

src/utils/installable.ts

@@ -1,13 +0,0 @@
-import { App } from 'vue';
-import { camelize } from './format/string';
-
-export function installable<T>(options: T) {
-  return {
-    ...options,
-    install(app: App) {
-      const { name } = options as any;
-      app.component(name, options);
-      app.component(camelize(`-${name}`), options);
-    },
-  };
-}