Remove artifacts from deprecated Elastic Endpoint in K8s project

[norrietaylor]

What does this PR do?

The Elastic Endpoint in K8s project has been deprecated. This PR cleans up artifacts that remained in the Agent YAML due to that project.

This PR is tested in the cloud-defend CI pipeline.

[mergify]

This pull request does not have a backport label. Could you fix it @norrietaylor? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 8./d branch. /d is the digit

NOTE: backport-skip has been added to this pull request.

[cmacknz]

Thanks!

[gizas]

The node autodiscovery of elastic agent is based (in one of the alternatives) to machine-id: https://github.com/elastic/elastic-agent-autodiscover/blob/e3da20d82e3f0fa03637f298d73d631cbd9b0068/kubernetes/util.go#L198

So the mounting of this /etc/machine-id is needed and not to be removed

[MichaelKatsoulis]

The node autodiscovery of elastic agent is based (in one of the alternatives) to machine-id: https://github.com/elastic/elastic-agent-autodiscover/blob/e3da20d82e3f0fa03637f298d73d631cbd9b0068/kubernetes/util.go#L198

So the mounting of this /etc/machine-id is needed and not to be removed

It is the last alternative in case the NODE_NAME env var is not set for any reason. I think it is ok to leave the mount there and update the comment to Needed for Kubernetes node autodiscovery

[elastic-sonarqube]

Quality Gate passed

Kudos, no new issues were introduced!

0 New issues
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube

[pierrehilbert]

@norrietaylor what is the plan with this PR? Still relevant?

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube

[norrietaylor]

This certainly slipped through the cracks. Apologies.

This is clean up, that we should probably do, as the Elastic Defend integration in K8s is no longer supported or distributed.

I made the changes requested by @gizas and @MichaelKatsoulis. If they give the LGTM, we can merge.