[8.x](backport #5556) Add pprofextension from the OTel-contrib

[mergify]

What does this PR do?

This comit adds the pprofextension to the OTel collector.

Why is it important?

As part of running benchmarks for Elastic-Agent we need to be able to take diagnostic profiles and as we onboard the OTel collector to the framework we need to enable Pprof for the OTel collector.

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

Once you have a packaged version of Elastic-Agent then you can start it with the following OTel config

#.... other stuff....
extensions:
    pprof:
        endpoint: localhost:5066
#... some other....
service:
    extensions:
        - pprof
    #.. other extensions

Related issues

• Relates: https://github.com/elastic/ingest-dev/issues/4027

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 #5556 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of aa56bc9 has failed:

On branch mergify/bp/8.x/pr-5556
Your branch is up to date with 'origin/8.x'.

You are currently cherry-picking commit aa56bc9622.
  (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
	new file:   changelog/fragments/1726739016-otel-pprof-extension.yaml
	modified:   internal/pkg/otel/components.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   go.mod
	both modified:   go.sum
	both modified:   internal/pkg/otel/README.md

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

[mauri870]

Looks like there are a couple git conflicts to be fixed.

[mergify]

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

[pchila]

Cherry-picked the commit again, isolating the original change from all the version bumps that got in the automatic backport. If we want to bump otel dependencies we should either backport the original PR or use the automation also on 8.x

@mauri870 could you have another look ?

updated the PR and kept only the original changes without the other version bumps

[alexsapran]

/test

[pchila]

Failures in TestAPMConfig may be caused by #5615 (there are HTTP 502/503 errors coming from the APM agent in the logs), need to retest once that fix has been merged

[mergify]

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

[pchila]

/test

[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 mergify/bp/8.x/pr-5556 upstream/mergify/bp/8.x/pr-5556
git merge upstream/8.x
git push upstream mergify/bp/8.x/pr-5556

[mergify]

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

[alexsapran]

/test

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube