I added a new option to the screenshot method to customize the color of
the box when we want to mask some elements for the screenshot.
The default color is pink `#FF00FF`, but with this new option you can
specify the color you like the most, like a nice green `#00FF00`:
```js
await page.screenshot({
mask: [page.locator('div').nth(5)],
maskColor: "#00FF00",
})
```
---------
Signed-off-by: Jasiel Guillén <darkensses@gmail.com>
- Never use open shadow root for highlight. This messes up
our selectors that accidentally match internal preview elements.
- Remove failing electron test that we do not care about.
- Skip `channels.spec.ts` in non-default mode.
