ECE vars - 9.x references probably need variables too, double check "human" version #s

[shainaraskas]

Type of issue

Other

What documentation page is affected

https://www.elastic.co/docs/deploy-manage/deploy/cloud-enterprise/ece-install-offline-with-registry

What happened?

these 9.x references should probably be using 9 latest

and also in https://www.elastic.co/docs/deploy-manage/upgrade/orchestrator/upgrade-cloud-enterprise these upgrade paths might need a human touch and not be automated. verify

Additional info

No response