Simplify hasFlags function for FlagBag.

[laurentmuller]

The function hasFlags() in the FlagBag class can be simplified. We can call the hasBits() function:

public function hasFlags(\BackedEnum ...$flags): bool
{
    $bits = static::encodeBits(array_map(static fn (\BackedEnum $flag) => $flag->value, $flags));

    return $this->hasBits($bits);
}