Puppeteer: using restart: false during tests will let browser stuck

Hi.
I'm trying to use persistent browser state with Puppeteer so multiple scenarios can be run without browser restarts between them. Since all other tests are arranged with the default restart config, I'm trying to use the dynamic `.config('restart: false')` in one single suite, like so:
```
Feature('My grouped tests in one feature').config({ restart: false });
// hooks and scenarios
```

Tests themselves behave exactly as intended. The problem is, after the last test finishes and passes, the browser will remain open, stuck, preventing the test queue to continue.

Since I'm running tests on a pipeline, this is preventing me to use this feature.

I noticed this have been reported before for WebDriverIO.

Is there any workaround for this?

まず、Puppeteer helper による動的な .config({ restart: false }) 設定の処理と、feature 完了後のブラウザーのライフサイクルを確認します。restart を無効にした状態でグループ化された feature を再現し、その後、デフォルトの restart 設定と比較して、最後のシナリオの後も test queue が継続することを検証します。

索引モデルが issue の本文から書いたものです。