[18.9] Fix AmazonLinux 2023 not working with epoll_pwait2 glibc call

What does this MR do and why?

This backports !9214 (merged) to 18-9-stable.

The io-event gem needs the epoll_pwait2 patch not just for EL 9, but for any distribution with glibc 2.34 that has backported epoll_pwait2 support. For example, AmazonLinux 2023.10.20260202 appears to have pulled in the RHEL changes (RHEL-101986) for this.

Replace the el_9? check with a new glibc_2_34? method that covers both EL 9 and AmazonLinux 2023, making the code more maintainable and accurate.

Relates to #9684

Describe in detail what merge request is being backported and why

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• This MR is backporting a bug fix, documentation update, or spec fix, previously merged in the default branch.
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