Create 1.28.0-bb.6 chart with 8.18.X images to fix upgrade pattern to 9.X

Fix the upgrade pattern to EK 9.X by going backward and creating a new 1.28-bb.6 chart with 8.18.X images

• The ek-operator no longer allows upgrading to 9.X from 8.17.X, and now strictly requires 8.18.X
• SOURCE

New Upgrade Path ✅ 1.28.0-bb.6 8.18.1 -> 1.30.0-bb.0 9.0.1

Current Upgrade Path ❌ 1.28.0-bb.5 8.17.4 -> 1.30.0-bb.0 9.0.1

ERROR:

Helm upgrade failed for release logging/logging-ek with chart elasticsearch-kibana@1.30.0-bb.0: cannot patch "logging-ek" with kind 
Elasticsearch: admission webhook "elastic-es-validation-v1.k8s.elastic.co" denied the request: Elasticsearch.elasticsearch.k8s.elastic.co 
"logging-ek" is invalid: spec.version: Invalid value: "9.0.0": Unsupported version upgrade path. Check the Elasticsearch documentation for supported upgrade paths.