delete unnecessary file

packages/app/src/models/serializers/activity-snapshot/user.ts

@@ -1,15 +0,0 @@
-import { IUser } from '~/interfaces/user';
-
-export type ISnapshot = {
-  actionUsername: string
-}
-
-export const stringifySnapshot = (user: IUser): string => {
-  return JSON.stringify({
-    username: user.username,
-  });
-};
-
-export const parseSnapshot = (snapshot: string): ISnapshot => {
-  return JSON.parse(snapshot);
-};