DO NOT MERGE [metricbeat][system/process] - Handle non-fatal errors

[VihasMakwana]

• Enhancement

Proposed commit message

With elastic/elastic-agent-system-metrics#164, we now also expect a list of non-fatal errors (access denied, operation not permitted, invalid parameters etc) which will be used to update status to DEGRADED.
In this PR, we just return the errors. #40025 would take care of changing the actual status to DEGRADED.
Also,

• update go.mod

Checklist

• 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.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Disruptive User Impact

Author's Checklist

• [ ]

How to test this PR locally

Related issues

• Closes [Elastic Agent] Allow Metricbeat metricsets to report their status to the Elastic Agent #39736

Use cases

Screenshots

Logs

[mergify]

This pull request does not have a backport label.
If this is a bug or security fix, could you label this PR @VihasMakwana? 🙏.
For such, you'll need to label your PR with:

• The upcoming major version of the Elastic Stack
• The upcoming minor version of the Elastic Stack (if you're not pushing a breaking change)

To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v8./d.0 is the label to automatically backport to the 8./d branch. /d is the digit

[mergify]

This pull request is now in conflicts. Could you fix it? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b metricbeat-process-multierr upstream/metricbeat-process-multierr
git merge upstream/main
git push upstream metricbeat-process-multierr

[elasticmachine]

Pinging @elastic/elastic-agent-data-plane (Team:Elastic-Agent-Data-Plane)

[elasticmachine]

Pinging @elastic/obs-ds-hosted-services (Team:obs-ds-hosted-services)

[VihasMakwana]

@cmacknz screenshot of error event on Kibana.

[VihasMakwana]

@elastic/obs-ds-hosted-services can someone from you team review this?

[mergify]

This pull request is now in conflicts. Could you fix it? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b metricbeat-process-multierr upstream/metricbeat-process-multierr
git merge upstream/main
git push upstream metricbeat-process-multierr

[mergify]

backport-8.x has been added to help with the transition to the new branch 8.x.