[`pyupgrade`] Remove `non-pep604-isinstance` (`UP038`) (#19156)
## Summary
This PR Removes deprecated UP038 as per instructed in #18727
closes #18727
## Test Plan
I have run tests non of them failing
One Question i have is do we have to document that UP038 is removed?
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Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
