Bump xmldom and appium in /tools/generate-screenshots

Removes [xmldom](https://github.com/xmldom/xmldom). It's no longer used after updating ancestor dependency [appium](https://github.com/appium/appium). These dependencies need to be updated together.


Removes `xmldom`

Updates `appium` from 1.14.0 to 1.22.3
- [Release notes](https://github.com/appium/appium/releases)
- [Changelog](https://github.com/appium/appium/blob/master/CHANGELOG.md)
- [Commits](appium/appium@v1.14.0...v1.22.3)

---
updated-dependencies:
- dependency-name: xmldom
  dependency-type: indirect
- dependency-name: appium
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>