[Unit|Backed]Enum is an interface

[BenMorel]

The manual for UnitEnum currently shows:

class UnitEnum {
    /* Methods */
    abstract public static cases(): array
}

When it should be:

interface UnitEnum {
    /* Methods */
    public static cases(): array
}

Sorry for not sending a PR, I'm still struggling with getting the doc build locally.

[cmb69]

Thank you!

[mumumu]

Also, we should fix BackedEnum.

class BackedEnum implements UnitEnum {
    /* Methods */
    abstract public static from(string|int $value): static
    abstract public static tryFrom(string|int $value): ?static
}

https://github.com/php/php-src/blob/d312a0c8007ffd398cbbb3cf9340db2654513cd6/Zend/zend_enum.stub.php#L10-L15

interface BackedEnum extends UnitEnum
{
    public static function from(int|string $value): static;

    public static function tryFrom(int|string $value): ?static;
}