TypeError: coi_module_implements_alter(): Argument #2 ($hook) must be of type string, int given

The change to allow string|int for the $hook argument in coi_module_implements_alter() is correct. This prevents a TypeError when Drupal incorrectly registers update hook numbers (e.g., 8001) as hook names, as described in issue #3508292. The fix ensures compatibility while keeping the existing logic intact.
Thus the changes looks good to me moving this to RTBC+!