Deprecation warning on filebeat installation

While installing filebeat using [the quickstart guide](https://www.elastic.co/docs/reference/beats/filebeat/filebeat-installation-configuration), I get the following error:
```
warning: posix.fork(): .fork(), .exec(), .wait() and .redirect2null() are deprecated, use rpm.spawn() or rpm.execute() instead
warning: posix.wait(): .fork(), .exec(), .wait() and .redirect2null() are deprecated, use rpm.spawn() or rpm.execute() instead
warning: posix.exec(): .fork(), .exec(), .wait() and .redirect2null() are deprecated, use rpm.spawn() or rpm.execute() instead
```

## More info
- **Version**: filebeat version 9.0.0 (amd64), libbeat 9.0.0 [42a721c925857c0d1f4160c977eb5f188e46d425 built 2025-04-08 14:08:17 +0000 UTC]
- **Operating System**: Fedora Server 41
- **Steps to Reproduce**: Install filebeat:
```
curl -L -O https://artifacts.elastic.co/downloads/beats/filebeat/filebeat-9.0.0-x86_64.rpm
sudo rpm -vi filebeat-9.0.0-x86_64.rpm
```

Start with the linked Filebeat quickstart guide and reproduce the installation using the provided curl and rpm -vi commands on Fedora Server 41. Check where the reported posix.fork, posix.wait, and posix.exec deprecation warnings originate during RPM installation; done means identifying and addressing the warning or documenting that it is external to Beats.

Written by the indexing model from the issue text.