Track Maestro PostgreSQL 15 upgrade (maestro values and statefulset templates)

[coderabbitai]

Summary

This issue tracks the decision and implementation of upgrading the Maestro component's PostgreSQL reference from postgresql_13 to postgresql_15 in the Helm templates.

Background

In PR #3061, the hack/bundle-automation/config.yaml was updated to map postgresql-15-c9s: postgresql_15 for the Assisted Service component. However, the Maestro templates still reference postgresql_13:

• pkg/templates/charts/toggle/maestro/values.yaml (line 8)
• pkg/templates/charts/toggle/maestro/templates/maestro.db.statefulset.yaml (line 32)

The Maestro team is still evaluating whether they wish to adopt PostgreSQL 15. Once a decision is made, these files should be updated accordingly.

Action Items

• Confirm with the Maestro component team whether they want to upgrade to PostgreSQL 15.
• If yes, update pkg/templates/charts/toggle/maestro/values.yaml to reference postgresql_15.
• If yes, update pkg/templates/charts/toggle/maestro/templates/maestro.db.statefulset.yaml to reference postgresql_15.

References

• PR: Added mce-release-version to bundle and chart configurations for MCE 2.17 #3061
• Review comment: Added mce-release-version to bundle and chart configurations for MCE 2.17 #3061 (comment)

Requested by: @dislbenn