fix: canary only worked when gateway enabled

[jacobcrawford]

What this PR does / why we need it:
The Loki Canary only worked when the gateway was enabled. We should support setting the Loki endpoint through values so it does not have as hard dependency to the gateway.

Which issue(s) this PR fixes:
Fixes #14233
Fixes #11208

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.

[JStickler]

Please note that /helm/reference.md is a generated file. You need to modify the template, not the generated file.

This note is at line 11 in the file. "Autogenerated. Modify ../production/helm/loki/reference.md.gotmpl "

[jacobcrawford]

These changes are the product of running make helm-docs in the root of the project:

I followed the contributing guide at: ./production/helm/loki/README.md is that not correct? 😃

[JStickler]

So the changes to reference.md came from running make helm-docs? If that's the case, you're fine. But if you manually edited the file, the changes will be overwritten the next time the file is generated.

[jacobcrawford]

Correct! The changes are only made from running make helm-docs and i have not made any manual changes to the docs 😄