message: feat(@vant/cli): support pnpm install
diff: +import fs from 'fs-extra';
  import execa from 'execa';
  +import { join } from 'path';
  import { consola } from './logger.js';
  import { execSync } from 'child_process';
  +import { ROOT } from './constant.js';
  let hasYarnCache: boolean;
  @@ -17,11 +20,16 @@ export function hasYarn() {
  return hasYarnCache;
  }
  +function isUsingPnpm() {
  + const pnpmLock = join(ROOT, 'pnpm-lock.yaml');
  + return fs.existsSync(pnpmLock);
  +}
  +
  export async function installDependencies() {
  consola.info('Install Dependencies\n');
  try {
  - const manager = hasYarn() ? 'yarn' : 'npm';
  + const manager = isUsingPnpm() ? 'pnpm' : hasYarn() ? 'yarn' : 'npm';
  await execa(manager, ['install', '--prod=false'], {
  stdio: 'inherit',
  