style: format code and improve readability

frontend/src/app/service/user.service.ts

@@ -42,13 +42,4 @@ export class UserService {
       this.currentUserSubject.next(updatedUser);
     }
   }
-
-  public createUser(id: string, username: string): Observable<User> {
-    return this.http
-      .post<User>('/backend/user', {
-        authentikId: id,
-        username: username,
-      })
-      .pipe(tap((user) => this.currentUserSubject.next(user)));
-  }
 }