I'm using spout for quite a while now. After upgrading php, and with that libxml, there is a huge issue.
Php >= 8 and/or libxml >= 2.9.0 by default setlibxml_disable_entity_loader(true);

This leads to the following error with any XLSX file in ReaderAbstract.php at line 130:
Could not open xxx for reading! (Warning: XMLReader::open(): Unable to open source data)

Usinglibxml_disable_entity_loader(false); should not be an option at all as it isdeprecated and opens up to XXE attacks.

Is there any other solution for this error?

EDIT:
I've made a protptye for demonstration:
Demo
Disabling the entity loader in line 58, as this is the php default, throws an exception.