TYPO3 Core

[[https://github.com/TYPO3/typo3/blob/main/typo3/sysext/core/Classes/Package/AbstractServiceProvider.php#L167]]

public static function configureIcons(ContainerInterface $container, \ArrayObject $icons, ?string $path = null): \ArrayObject
{
    $path = $path ?? static::getPackagePath();
    $iconsFileNameForPackage = $path . 'Configuration/Icons.php';
    if (file_exists($iconsFileNameForPackage)) {
        $definedIconsInPackage = require $iconsFileNameForPackage;//<-- Here the Icons.php is called
        //Code from Icons.php is executed
        //$icons = somethingThatsNotAnArrayObject

        if (is_array($definedIconsInPackage)) {
            //Now $icons is probably not an ArrayObject anymore, and $icons->exchangeArray() is called
            $icons->exchangeArray(array_merge($icons->getArrayCopy(), $definedIconsInPackage));
            // e.g. array()->exchangeArray() will lead to an error
        }
    }
    return $icons;
}

This code from the AbstractServiceProvider, with my comments should display how the bug comes to life.
It is in the Code since 11.5 as far as I have seen.
Can you please wrap the inclusion of the Icons.php in a new function?

public static function requirePHPFile(string $filepath): mixed 
{
    //this protects the local variables from being changed accidentally by another user/developer
    return require $filepath;
}

I just found this version being used:
[[https://github.com/TYPO3/typo3/blob/13.1/typo3/sysext/core/Classes/Configuration/Tca/TcaFactory.php#L109]]

// To require TCA in a safe scoped environment avoiding local variable clashes.
// Note: Return type 'mixed' is intended, otherwise broken TCA files with missing "return [];" statement would
//       emit a "return value must be of type array, int returned" PHP TypeError. This is mitigated by an array
//       check below.
$scopedReturnRequire = static function (string $filename): mixed {
    return require $filename;
};