BUG: Yarn Berry Installation not supported

[kneekeel]

We have recently migrated our repositories from Yarn Classic -> Yarn Berry. The equivalent installation for packages is yarn install --immutable.

Suggestion

Update this line to:

    const yarnLock = fs.existsSync(path.resolve(workingDir, 'yarn.lock'))
    const isYarnBerry = fs.existsSync(path.resolve(workingDir, '.yarnrc.yml'))
    const packageLock = fs.existsSync(path.resolve(workingDir, 'package-lock.json'))
  

    let installScript = `npm install --production=false`
    if (yarnLock) {
      installScript = `yarn ${isYarnBerry ? '--immutable' :  '--frozen-lockfile'}`
    } else if (packageLock) {
      installScript = `npm ci`
    }

Happy to put in a PR.