Found via #660

Even though already macOS package is not supported in 5.x series,
Now macOS workflow always fails because of refreshed runner image

https://github.com/fluent/fluent-package-builder/actions/runs/10105868174/job/27947051208
macos-14-arm64 20240722.3 causes failure.
(failure of building jemalloc)

https://github.com/fluent/fluent-package-builder/actions/runs/10091587427/job/27903442530
until version macos-14-arm64 20240714.2, it succeeds.

So, disable macos.yml workflow manually, then enable it again if we support it.