Bump appium-xcuitest-driver from 7.20.1 to 7.21.2

Bumps [appium-xcuitest-driver](https://github.com/appium/appium-xcuitest-driver) from 7.20.1 to 7.21.2.
- [Release notes](https://github.com/appium/appium-xcuitest-driver/releases)
- [Changelog](https://github.com/appium/appium-xcuitest-driver/blob/master/CHANGELOG.md)
- [Commits](appium/appium-xcuitest-driver@v7.20.1...v7.21.2)

---
updated-dependencies:
- dependency-name: appium-xcuitest-driver
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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