feat(helm): canary can be set as a deployment

[hervenicol]

What this PR does / why we need it:

By default, canary was created as a daemonset. Meaning write path was tested for each node of the cluster. However, when you have one loki on a cluster, but the clients sending logs run on some other clusters, it does not make much sense anymore to have that many canary pods. So, if you just want to test the write path works, a deployment with a few canary pods is enough.

This PR adds the option to deploy canary pods as a deployment instead of a daemonset.

Special notes for your reviewer:

Checklist

• [x] Reviewed the CONTRIBUTING.md guide (required)
• [x] Documentation added
• [ ] Tests updated
• [x] 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
• [x] For Helm chart changes bump the Helm chart version in production/helm/loki/Chart.yaml and update production/helm/loki/CHANGELOG.md and production/helm/loki/README.md. Example PR
• [ ] 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

[QuentinBisson]

@MichelHollands I know we need to rebase this to fix conflicts but what do you think about the underlying PR?

[QuentinBisson]

hey @chaudum do you think we could have a review on this PR from the team?