[8.x](backport #5654) feat: implement custom mockes and drop go-metrics

[mergify]

What does this PR do?

implement a custom mockes and get rid of go-metrics and related deps

Why is it important?

go-metrics hasn't been updated in 4 years

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/fragments using the changelog tool
• I have added an integration test or an E2E test

Disruptive User Impact

How to test this PR locally

Related issues

Blocked by elastic/mock-es#9

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?
• ...

---

This is an automatic backport of pull request #5654 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of e511550 has failed:

On branch mergify/bp/8.x/pr-5654
Your branch is up to date with 'origin/8.x'.

You are currently cherry-picking commit e51155073a.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   NOTICE.txt
	modified:   testing/integration/logs_ingestion_test.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   go.mod
	both modified:   go.sum

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[mergify]

This pull request has not been merged yet. Could you please review and merge it @kruskall? 🙏