fix: update loki-helm-test image tag to latest commit

[puretension]

What this PR does / why we need it:

Updates the loki-helm-test image tag from an outdated feature branch tag (ewelch-distributed-helm-chart-17db5ee) to latest.
This resolves security vulnerabilities in the helm test image identified in issue #19162 and ensures helm tests pass consistently.

Which issue(s) this PR fixes:
Fixes #19162

Special notes for your reviewer:

The previous tag ewelch-distributed-helm-chart-17db5ee was from a contributor's feature branch and contained security
vulnerabilities as reported in #19162. Using latest tag ensures we always use the most recent secure image build and prevents future occurrences of this issue.

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

[JStickler]

@slim-bean FYI, I assume you might have set this value in the tests back when you were working on updating the Helm charts?

[slim-bean]

i think maybe this should just be set to match the same version used for the loki image and enterprise logs image?

[puretension]

You're absolutely right! I've updated the implementation to use .Chart.AppVersion instead of a hardcoded commit hash.
This ensures the loki-helm-test image automatically matches the main loki image version.
Thank you for thefeedback!

[puretension]

Hi @JStickler,

I apologize for the test failure in my previous commit. I've now updated the implementation to use tag: "latest" for the loki-helm-test image, which resolves the image pull failure that was causing the helm tests to fail.

The issue was that grafana/loki-helm-test:3.5.3 doesn't exist on Docker Hub, but latest tag is available and working.

Thanks to this debugging process, I gained a deeper understanding of how Helm chart image resolution works and the importance of verifying image availability before implementation.

Could you please re-run the merge when you have a chance? The tests should pass now.

Thank you for your patience!

[puretension]

Hi @JStickler,

I sincerely apologize for the multiple iterations on this PR. I wasn't initially aware that documentation updates were required for Helm chart changes, which caused the previous merge attempts to fail. This experience has taught me how thorough and precise Loki's merge policies are.

All changes are now complete:

• Updated loki-helm-test image tag to "latest"
• Updated Helm template logic in _helpers.tpl
• Updated reference documentation (docs/sources/setup/install/helm/reference.md)

The PR should now be ready for final merge. Thank you for your patience and guidance throughout this process! 🙏

[JStickler]

@puretension no need to apologize for test failures, nobody expects perfection all the time (that's why we have tests!).