fix: fluent-bit K8s enrichment

[lemaitre-aneo]

Motivation

Log enrichment for kubernetes metadata was not working when fluent-bit was configured on daemon-set.

Description

Configure fluent-bit to fetch kubernetes metadata from Kupe-API instead of kubelet, which was not working.
It also remove the unused volume mount on the sidecar that was failing deployment on hosts without /var/fluent-bit/state/

Testing

Tested on locahost with K3s and docker.

Impact

Apart from fixing the bug, there is no impact.

Checklist

• My code adheres to the coding and style guidelines of the project.
• I have performed a self-review of my code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• I have thoroughly tested my modifications and added tests when necessary.
• Tests pass locally and in the CI.
• I have assessed the performance impact of my modifications.