Update full-mac-setup.md to include note about AppleID login in virtualized environments

[mordonez]

Update full-mac-setup.md to alert the step "Sign in in App Store " can't be tested in virtualized environments like UTM because AppleId login fails.

See for more info AppleID Login failing in virtualized OS

[github-actions]

This issue has been marked 'stale' due to lack of recent activity. If there is no further activity, the issue will be closed in another 30 days. Thank you for your contribution!

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