Delete key on One2Many without add_remove raise AttributeError
The shortcut added by #8180 (closed) crashes if the One2Many does not have add_remove attribute because it does not have a but_remove.
This instance will be upgraded to Heptapod 1.3.3 (GitLab 16.9.6) on 2023-04-25 at 18:00 UTC+2
The shortcut added by #8180 (closed) crashes if the One2Many does not have add_remove attribute because it does not have a but_remove.