feat(restarter): switch to rancher/kubectl image with auto versioning

[witalisoft]

bitnami will only release container images with the latest tag (announcement)

[CLAassistant]

All committers have signed the CLA.

[Copilot]

Pull Request Overview

This PR migrates the restarter component from the bitnami/kubectl image to rancher/kubectl with automatic Kubernetes version alignment. The change addresses Bitnami's decision to only release container images with the latest tag going forward.

• Switches from bitnami/kubectl to rancher/kubectl image repository
• Implements automatic version tagging that matches the Kubernetes cluster version when tag is set to .auto
• Refactors the CronJob template to use kubectl args instead of bash commands

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
charts/netdata/values.yaml	Updates default image repository to rancher/kubectl and sets tag to .auto
charts/netdata/templates/restarter/cronjob.yaml	Refactors command execution from bash script to kubectl args and implements auto-versioning logic
charts/netdata/README.md	Updates documentation to reflect new image repository and auto-versioning feature

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