[Php81] Add scalar type on Enum MyCLabsClassToEnumRector and SpatieEnumClassToEnumRector

[samsonasik]

To avoid error:

PHP Fatal error:  Case REFACTORING of non-backed enum Rector\Core\Enum\ApplicationPhase must not have a value, try adding ": string" to the enum declaration in /home/runner/work/rector-src/rector-src/vendor/rector/rector-src/src/Enum/ApplicationPhase.php on line 12
Error: Process completed with exit code 255.

ref #1364 (comment)

[samsonasik]

Fixed 🎉

[samsonasik]

All checks have passed 🎉 @TomasVotruba it is ready for review.

[TomasVotruba]

Thank you 👍