support sidecar containers feature (kubernetes 1.29)

[jackskj]

Crashing telegraf container (due to OOM or erroneous configuration) has effect on the main application as the state of the entire pod is set to "not ready" if telegraf is restarted.
In such occurrence, the entire pod will be taken out of kubernetes endpoints and service.

To overcome this issue, kubernetes 1.29 has a "sidecar container" beta feature.
With this feature, the lifecycle of the main pod is separate to that of any sicecar containers.

To implement this feature, telegraf-operator would have to be injected as an iniContiner with restartPolicy set to "always"

Relevant URLs

kubernetes 1.29 sidecar feature

What products and version are you using?

telegraf-operatror: v1.3.11
kubernetes v1.23 (planning to update)