[8.x](backport #41119) Add a known issue entry for 8.15.0 and 8.15.2 referencing https://github.com/elastic/beats/issues/41118

[mergify]

Proposed commit message

See title

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

• Documents: Beats do not log to stderr when running in a container or systemd environment #41118

## Use cases
## Screenshots
## Logs

---

This is an automatic backport of pull request #41119 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 9d87afa has failed:

On branch mergify/bp/8.x/pr-41119
Your branch is up to date with 'origin/8.x'.

You are currently cherry-picking commit 9d87afaaf3.
  (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)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   CHANGELOG.asciidoc

no changes added to commit (use "git add" and/or "git commit -a")

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

[botelastic]

This pull request doesn't have a Team:<team> label.

[mergify]

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

[mergify]

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

[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-41119 upstream/mergify/bp/8.x/pr-41119
git merge upstream/8.x
git push upstream mergify/bp/8.x/pr-41119

[mergify]

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

[mergify]

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

[mergify]

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

[mergify]

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