[8.x](backport #5941) Add os_family, os_platform and os_version to host provider

[mergify]

What does this PR do?

This commit adds os_family, os_platform and os_version to the host provider, enabling differentiating Linux distributions. This is required to support Debian 12 and other distributions that are moving away from traditional log files in favour of Journald.

Why is it important?

It is required to support Debian 12 and other Linux distributions that are moving away from traditional log files in favour of Journald.

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

None

How to test this PR locally

1. Package the Elastic-Agent
2. Deploy it with any policy, even an empty policy with no monitoring will work
3. Collect the diagnostics
4. Look at variables.yml and ensure os_family, os_platform and os_version are populated under host. Here is an example from Debian 11:

      host:
        architecture: x86_64
        id: 9a7aa218396d47b1b17218a99918bae4
        ip:
            - 127.0.0.1/8
            - 10.0.2.15/24
            - ::1/128
            - fe80::a00:27ff:fe8d:c04d/64
        mac:
            - 08:00:27:8d:c0:4d
        name: bullseye
        os_family: debian
        os_platform: debian
        os_version: 11 (bullseye)
        platform: linux

Related issues

• Relates Investigate the best way to decide when to read system logs from files or journald integrations#10797
• Is required by [System] Add journald support for auth and syslog data streams integrations#11618

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 #5941 done by [Mergify](https://mergify.com).

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarQube