Simplify castBinding() by removing redundant enum check

Changes

This PR simplifies the castBinding method by removing the redundant instanceof UnitEnum check and directly calling enum_value().

Rationale

The current implementation checks if the value is a UnitEnum before calling enum_value():

public function castBinding($value)
{
    if ($value instanceof UnitEnum) {
        return enum_value($value);
    }

    return $value;
}

However, the enum_value() helper already handles all these cases internally using a match expression:

function enum_value($value, $default = null)
{
    return match (true) {
        $value instanceof \BackedEnum => $value->value,
        $value instanceof \UnitEnum => $value->name,
        default => $value ?? value($default),
    };
}

Since enum_value() already returns the original value when it's not an enum (via the default case), we can simplify castBinding to:

public function castBinding($value)
{
    return enum_value($value);
}

Benefits

• Removes duplication: Eliminates redundant enum type checking
• Cleaner code: Reduces one conditional statement and one return statement
• Single source of truth: All enum handling logic stays in enum_value()
• Same behavior: No functional changes, just simplified code