fix(helm): properly forward queries to ruler

[mcanevet]

What this PR does / why we need it: When using Ingress instead of gateway with simple scalable mode, ruler paths are currently redirected to reader instead of backend.

Checklist

• [x] Reviewed the CONTRIBUTING.md guide (required)
• [ ] Documentation added
• [ ] Tests updated
• [x] Title matches the required conventional commits format, see here
• [ ] 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

[CLAassistant]

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