Update ELASTIC_AGENT_REPO_PATH in Makefile

[kpollich]

What does this PR do?

Updates the Elastic Agent manifest file path in Kibana, which changed last year and resulted in this sync process failing for months without anyone noticing.

Why is it important?

Kibana relies on this automation to keep the Kubernetes manifests displayed during agent enrollment up to date with any changes made on the agent side.

Checklist

• I have read and understood the pull request guidelines of this project.
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in ./changelog/fragments using the [changelog tool](https://github.com/elastic/elastic-agent#changelog)
• I have added an integration test or an E2E test

Disruptive User Impact

No

How to test this PR locally

N/A

Related issues

Questions to ask yourself

• How are we going to support this in production?
• How are we going to measure its adoption?
• How are we going to debug this?
• What are the metrics I should take care of?
• ...

[mergify]

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

• backport-./d./d is the label that automatically backports to the 8./d branch. /d is the digit
• backport-active-all is the label that automatically backports to all active branches.
• backport-active-8 is the label that automatically backports to all active minor branches for the 8 major.
• backport-active-9 is the label that automatically backports to all active minor branches for the 9 major.

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[elasticmachine]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 78a7a17

Failed CI Steps

• 📦 arm64: Containers

History

cc @kpollich

[norrietaylor]

@cmacknz @ebeahan

Is it reasonable to expect that this will allow edits to the manifest to reach production for 9.3? Our team has some recent changes we would like to see served up by Kibana cc/ @mjwolf

[ebeahan]

@norrietaylor Merging this PR triggered the necessary BK job and created elastic/kibana#247970.

@kpollich and team will need to merge and then backport that PR for the changes to go out in 9.3.

[norrietaylor]

@norrietaylor Merging this PR triggered the necessary BK job and created elastic/kibana#247970.

Thanks kindly!