There's a merged pull request on the void-packages repository

haproxy: update to 2.6.9.
https://github.com/void-linux/void-packages/pull/42194

Description:
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#### Testing the changes
- I tested the changes in this PR: **YES**

#### Local build testing
- I built this PR locally for my native architecture, (x86_64-glibc)
- I built this PR locally for these architectures (if supported. mark crossbuilds):
  - aarch64-musl

HAProxy 2.6 is the latest LTS release with some nice improvements over the 2.4 series. Until another LTS hits, it's reasonable to lock the package to 2.6.x.