Moodle does not use install.xml files for upgrades, it uses upgrade.php files (the code for which can also be generated by the xmldb editor).
See: https://docs.moodle.org/dev/Upgrade_API#The_files_you_need_for_the_second_release
Moodle does not use install.xml files for upgrades, it uses upgrade.php files (the code for which can also be generated by the xmldb editor).
See: https://docs.moodle.org/dev/Upgrade_API#The_files_you_need_for_the_second_release