[packaging] Retire init.d support in linux packages

[arvchristos]

Auditbeat clashes with chkconfig under Alma 9

During its install on Alma 9, auditbeat creates /etc/init.d and drops a file into it. This is preventing chkconfig from installing correctly.
The package chkconfig expects /etc/init.d not to exist, in order to create a synlink in its place.

This happens on Alma 9 and leaves the setup in a wrong state, which is reported as an error by 'dnf check'.

The init.d scripts should not be needed for recent Alma/RHEL versions.

[Neurozone]

Same issue with filebeat, you need to remove asap this service file as it will never be used in the future anymore !

[elasticmachine]

Pinging @elastic/sec-linux-platform (Team:Security-Linux Platform)

[andrewkroh]

The init.d scripts should not be needed for recent Alma/RHEL versions.

We dropped support of RHEL 6 during the 8.0.0 release so there shouldn't be any operating system left on our support matrix that require init.d files. I think they are safe to remove.

[andrewkroh]

I see I commented about this in #35708 (comment). Since then I think the OS matrix has been updated to remove Amazon Linux 1. I'm going to lazily re-title this to reflect that we should remove init.d.