feat(helm): add configurable livenessProbe to single binary StatefulSet

[unique-jakub]

• Add livenessProbe support to single binary StatefulSet using global loki.livenessProbe configuration
• Maintains consistency with other Loki components' probe configuration patterns

What this PR does / why we need it:

This PR adds support for configurable livenessProbe to the single binary StatefulSet deployment mode. Currently, the single binary StatefulSet only supports readinessProbe but lacks livenessProbe configuration, which is available in other Loki components.

The implementation uses the global loki.livenessProbe configuration (similar to how other components like distributor, querier, and index-gateway handle probes), ensuring consistency across the entire chart.

This enables users to:

• Configure custom liveness probe settings for better health monitoring
• Customize probe timing (initialDelaySeconds, periodSeconds, etc.) based on their deployment requirements
• Improve Pod lifecycle management in Kubernetes environments

Which issue(s) this PR fixes:
Fixes #15191

Special notes for your reviewer:

• The implementation follows the same pattern used by other Loki components (distributor, querier, index-gateway, etc.) which use {{- with .Values.loki.livenessProbe }}
• No breaking changes - existing deployments continue to work unchanged since loki.livenessProbe defaults to {}
• The single binary StatefulSet now has feature parity with other deployment modes regarding probe configuration

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.

[jkroepke]

LGTM

[Jayclifford345]

LGTM!