core&utils: remove outdated code

packages/hydrooj/src/utils.ts

@@ -1,5 +1,3 @@
-import type { Logger } from './logger';
-
 export function buildProjection(fields: string[]): Record<string, 1> {
     const o = {};
     for (const k of fields) o[k] = 1;
@@ -18,21 +16,4 @@ export function ArgMethod(target: any, funcName: string, obj: any) {
     return obj;
 }
 
-export function logAndReturn(logger: Logger) {
-    return function cb(err: Error) {
-        logger.error(err);
-        return err;
-    };
-}
-
-const RE_USER = /(?:^|\s)(@)([^ ]{3,255}?)(?=\s|$)/g;
-
-export function getRelatedUsers(content: string) {
-    const results = [];
-    let res: string[];
-    // eslint-disable-next-line no-cond-assign
-    while (res = RE_USER.exec(content)) results.push(res[2]);
-    return results;
-}
-
 export * from '@hydrooj/utils/lib/utils';