[8.x] [Filebeat] Add known issue for clean_inactive in

[belimawr]

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

• Filestream reingests data when clean_inactive is set #45601

## Use cases
## Screenshots
## Logs

[elasticmachine]

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

[vishaangelova]

LGTM. Left some comments for your consideration.

[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 8.19-45601-clean-inactive-known-issues upstream/8.19-45601-clean-inactive-known-issues
git merge upstream/8.19
git push upstream 8.19-45601-clean-inactive-known-issues