Reliability - Availability zones by region - Remove duplicate regions

[prmerger-automator[bot]]

@johndowns : Thanks for your contribution! The author(s) have been notified to review your proposed change. @anaharris

[learn-build-service-prod[bot]]

Learn Build status updates of commit 8208124:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
articles/reliability/availability-zones-service-support.md	:white_check_mark:Succeeded

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel