[Integration Name]: Brief description of the issue

### Integration Name

Linux Metrics [packages/linux]

### Dataset Name

linux.service

### Integration Version

1.1.0

### Agent Version

8.19.14

### Agent Output Type

elasticsearch

### Elasticsearch Version

8.19.14

### OS Version and Architecture

RHEL 8.8 and 9.6

### Software/API Version

_No response_

### Error Message

Error fetching data for metricset system.service: error getting list of running units: dbus: connection closed by user.

### Event Original

_No response_

### What did you do?

The issue can be resolved by restarting the Elastic Agent service.

### What did you see?

The agent switches to an "Unhealthy" state, stops sending data, and instead creates documents containing the attached error.

### What did you expect to see?

Automatic recovery of the agent if the connection to D-Bus is closed for any reason.

### Anything else?

_No response_

Start in the Linux Metrics integration under packages/linux, focusing on the system.service metricset and its handling of closed D-Bus connections. Reproduce the failure with the reported RHEL versions and verify that the Elastic Agent recovers automatically and resumes sending data without a service restart.

Written by the indexing model from the issue text.