Update CI to make use of env variable from opendatahub-operator instead of CSV

[ChristianZaccaria]

WHY

The CFO will eventually no longer be deployed as a subscription through OperatorHub. Instead, the opendatahub-operator will be deploying the CFO.

WHAT

The CI currently installs the CFO via the subscription. Once the new deployment option is available, the CI will need to be updated/adjusted.

HOW

The CI runs on a HyperShift cluster. A suggested solution would be to make use of the OpenShift Internal Registry to build and push a custom image of the CFO. This way, within the cluster we can point the env variable from the opendatahub-operator to our custom image on PRs made, to be ran on the CI.

https://github.com/openshift/release/blob/a3f8ad5080a648a128a1ea272091b91707987301/ci-operator/config/opendatahub-io/codeflare-operator/opendatahub-io-codeflare-operator-main.yaml#L40-L63