operator: Drop OCP 4.10 & 4.11 support in community-openshift bundle

[periklis]

What this PR does / why we need it:
Based on #9457 we need to set the minimum required OCP version to 4.12 for the community OpenShift bundle releases.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• CHANGELOG.md updated
  • If the change is worth mentioning in the release notes, add add-to-release-notes label
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• For Helm chart changes bump the Helm chart version in production/helm/loki/Chart.yaml and update production/helm/loki/CHANGELOG.md and production/helm/loki/README.md. Example PR

[JoaoBraveCoding]

lgtm

[xperimental]

I first paused, because I thought this should require changes in the generated files, but it turns out that we only use this in the operatorhub.sh ...