OLM must be the only one way to deploy Eclipse Che on OpenShift

[tolusha]

Is your task related to a problem? Please describe

Currently we support only olm installer for OpenShift platform. But there is ability to deploy via yaml templates mainly for testing purpose. It caused [1]. We must get rid of this type of installation.

https://github.com/eclipse/che/issues/21603

Describe the solution you'd like

The list of tasks:

• [x] chectl must throw an error when --installer operator --platform <openshift|crc>
• [ ] Don't generate yaml templates for OpenShift on che-operator side
• [ ] Remove PR checks for chectl and che-operator which use yaml templates to deploy Eclipse Che

Describe alternatives you've considered

No response

Additional context

No response