Error 500 on Vendor Model report

[calvaradESU]

Discussed in #1443

^{Originally posted by calvaradESU September 15, 2023}
When I try to run a Vendor Model report I get an error 500, and this in apache log:

[Fri Sep 15 15:02:11.051322 2023] [php:error] [pid 1043189] [client 10.222.24.44:50173] PHP Fatal error: Uncaught Error: Undefined constant PhpOffice\PhpSpreadsheet\Collection\CellsFactory::cache_in_memory_serialized in /var/www/openDCIM-23.02/report_vendor_model.php:96\nStack trace:\n#0 {main}\n thrown in /var/www/openDCIM-23.02/report_vendor_model.php on line 96, referer: https://dcim.emporia.edu/report_vendor_model.php

This also happens on the demo site.