Fix shrinked viewport for devtools package

[L0tso]

Proposed changes

Fix #6471

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• I have added proper type definitions for new commands (if appropriate)

Further comments

Reviewers: @webdriverio/project-committers

[christian-bromann]

@L0tso can you run the tests and see if they pass?

[L0tso]

@christian-bromann Ohh, I thought PR was opened as draft :(
I have got some issues with this fix

1. TS error from Puppeteer
   Type 'null' is not assignable to type 'Viewport | undefined' [7.0.4] Type defaultViewport can't be null (to take all window space) puppeteer/puppeteer#6885
2. Broken snapshots
   
   Should I close PR until the issues isn't resolved? Or add // @ts-ignore and update snapshots?

[christian-bromann]

Please update your branch and update the screenshot, thanks!

[dylang]

This might be related to the issue that @L0tso is running into:
puppeteer/puppeteer#6885

[dylanlive]

Watching this. I may want to pull it into #6508 if it is merged.

[christian-bromann]

LGTM, thanks 👍