Reinstate FF_RETRIEVE_POD_WARNING_EVENTS in 17.x.x releases due to early removal in 17.2

Summary

FF_RETRIEVE_POD_WARNING_EVENTS was scheduled for deprecation in %17.2 and future removal in %18.0 but was accidentally removed in %17.2

Promote FF_RETRIEVE_POD_WARNING_EVENTS to a config print_pod_warning_events

After investigations, it also looks like the feature flag was mistakenly removed in this MR: Always attempt to retrieve pod warning events (!4852 - merged) 😞

Steps to reproduce

.gitlab-ci.yml

Add the job definition that is failing here

Actual behavior

It is not currently possible to disable the FF

Expected behavior

It should be possible to disable the FF

Relevant logs and/or screenshots

job log

Add the job log

Environment description

config.toml contents

Add your configuration here