Allow to save one2many with readonly attribute
From msg31809: when One2Many has a readonly attribute, the existing line could still be modified since #5041 (closed). So the value of such field should still be saved.
This instance will be upgraded to Heptapod 1.3.3 (GitLab 16.9.6) on 2023-04-25 at 18:00 UTC+2
From msg31809: when One2Many has a readonly attribute, the existing line could still be modified since #5041 (closed). So the value of such field should still be saved.