fix: Missing password for Loki-Canary when loki.auth_enabled is true

[win5923]

What this PR does / why we need it:

When loki.auth_enabled is true, loki-canary cannot set a password. Add a password parameter to address this issue. Additionally, the functionality can also be achieved through existSecret, but this PR does not implement that feature.

Which issue(s) this PR fixes:
Fixes #10873

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• CHANGELOG.md updated
  • If the change is worth mentioning in the release notes, add add-to-release-notes label
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• 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

[CLAassistant]

All committers have signed the CLA.

[win5923]

Hi @JStickler, this PR is ready. If there are any issues, please let me know. Thank you!

[JStickler]

@win5923 I'm the technical writer on the team so I don't approve code PRs, but I tagged someone who can.

[win5923]

@MichelHollands. Would you be able to review?

[MichelHollands]

@win5923 Thanks for the contribution. If you rebase/merge on the latest version then I'll approve this.

[win5923]

@win5923 Thanks for the contribution. If you rebase/merge on the latest version then I'll approve this.

Done!

[MichelHollands]

@win5923 Thanks for the contribution. If you rebase/merge on the latest version then I'll approve this.

Done!

Thanks but something went wrong. The new version should be 6.3.2

[MichelHollands]

@win5923 1 more change is needed. The documentation needs to be updated. Please run the command mentioned in the failing CI step.

[win5923]

Sorry for the delay, it's done!