Make package PHP 8 compatible

[dwenzel]

Do you consider supporting recent PHP versions?

Currently there are deprecation messages and errors when using this package with PHP 8.1 and 8.2.

PHP Deprecated:  Return type of Naucon\File\FileAbstract::getExtension() should either be compatible with SplFileInfo::getExtension(): string, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/.build/vendor/naucon/file/src/FileAbstract.php on line 77
PHP Deprecated:  Return type of Naucon\File\FileAbstract::getSize() should either be compatible with SplFileInfo::getSize(): int|false, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/.build/vendor/naucon/file/src/FileAbstract.php on line 729
PHP Fatal error:  Declaration of SplFileInfo::getBasename(string $suffix = ""): string must be compatible with Naucon\File\FileInfoInterface::getBasename($suffix = null) in /var/www/html/.build/vendor/naucon/file/src/FileAbstract.php on line 0