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.

[jacobcrawford]

@JStickler is anything holding us back from completing this PR?

[jacobcrawford]

@slim-bean or @knylander-grafana maybe one of you can review this super small PR. We are a company that would really appreciate being able to use the loki-canary deployment 😄

[slim-bean]

LGTM thanks!

[jacobcrawford]

@slim-bean thank you for the review! 😄
Merging is blocked because im not authorized to push to your branch. Is the process normally that you merge the PR?
Or maybe the workflows also need to be approved by a maintainer?

[slim-bean]

yeah we have to restrict running workflows to be approved by maintainers and we are also the only folks with merge access.

I just kicked off CI will try to merge it as soon as it finishes!