Add xros as supported platform everywhere appletvos appears

[demonnic]

Checklist

• I've run bundle exec rspec from the root directory to see all new and existing tests pass
• I've followed the fastlane code style and run bundle exec rubocop -a to ensure the code style is valid
• I see several green ci/circleci builds in the "All checks have passed" section of my PR (connect CircleCI to GitHub if not)
• I've read the Contribution Guidelines
• I've updated the documentation if necessary.
• I've added or updated relevant unit tests.

Motivation and Context

Adds xros to valid platform options to support the new Apple Vision Pro

Description

I previously added xros to deliver for uploads with #21841 and was able to test that myself, but I do not use the deliver functionality or other fastlane actions I modified so while the specs pass I am hoping to get some assistance with the functional testing.

Testing Steps