feat(helm): Enable rules sidecar for the ruler pods

[madaraszg-tulip]

What this PR does / why we need it:

Currently there is no way to deploy loki rules in an automated way when running in distributed mode. The recommended way is to deploy the rules using lokitool to the object storage, however there is no automation provided for that in the helm chart.

Simple scalable mode provided a rules sidecar to the backend pods which automatically imported rules from kubernetes configmaps and secrets. Implement the same sidecar for the ruler pods, gated by the ruler.sidecar switch which defaults to false.

Which issue(s) this PR fixes:
Fixes #16529

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[CLAassistant]

All committers have signed the CLA.

[Jayclifford345]

Thanks for adding this @madaraszg-tulip! Shall bring up at the Loki engineering call today

[Jayclifford345]

@madaraszg-tulip would you mind fixing the failed test I belive it just needs a docs update: helm-docs

[poyzannur]

Hi there, thanks for the contribution
Could you please include a changelog entry?

[madaraszg-tulip]

Hi there, thanks for the contribution Could you please include a changelog entry?

Sure I can, I didn't think I'd need to do it because the CONTRIBUTING doc says the following:
The PR title will appear in a changelog, so help other people understand what your change will be.

So what's the procedure to provide a changelog entry? CHANGELOG.md seems to be autogenerated

[JStickler]

There is a separate CHANGELOG for the Loki Helm chart.

https://github.com/grafana/loki/blob/main/production/helm/loki/CHANGELOG.md

[madaraszg-tulip]

There is a separate CHANGELOG for the Loki Helm chart.

https://github.com/grafana/loki/blob/main/production/helm/loki/CHANGELOG.md

Thanks, updated

[ncorreia]

Hello, when will this change be released?