fix(helm): fix queryScheduler servicemonitor

[rlex]

What this PR does / why we need it: Loki Query Scheduler had wrong targetPort for metrics port, which caused serviceMonitor to miss it.

Which issue(s) this PR fixes: N/A

Special notes for your reviewer:

Checklist

• [x] Reviewed the CONTRIBUTING.md guide (required)
• [x] 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]

All committers have signed the CLA.

[JStickler]

Please also bump the version number in production/helm/loki/README.md.

[rlex]

done

[rlex]

Any chance it will be merged? Along with #12766