Please read RFC for better formatting and full scope. The excerpt below is just to indicate the scope covered by this specific issue.

Need to update code to respect .spec.upgradeConstraintPolicy accordingly to the RFC:

When .spec.upgradeConstraintPolicy is set to Ignore we do not apply upgrade constraints. This means an Operator can be transitioned to any available version of the package (even one older than the currently installed one). Note that, if set, other constraints on Operator still apply (e.g. .spec.version and .spec.channel).

When .spec.upgradeConstraintPolicy is set to Enforce we use either semver or legacy semantics depending on the position of the ForceSemverUpgradeConstraints feature gate.

Acceptance criteria:

• It is possible to enforce semver or legacy semantics based on a feature gate
• It is possible to ignore upgrade constraints (and e.g. downgrade an operator)
• Tests are provided for both Ignore and Enforce