Mark the module as obsolete and provide an upgrade path

Never mind, the module isn't actually obsolete: it provides 'update/delete own' permissions that core doesn't provide. This means that we should create a new version that converts part of the permissions to the ones provided by core, while keeping the others in this module.

What we could do is log a message in the update hook in case no roles are using permissions provided by this module anymore, which means that the module can be removed.

I implemented the update hook. I tried to let the update hook uninstall the module, but apparently that's not supported (yet): 🐛 Support uninstalling the module providing the update hook in hook_update_N Needs work .

This looks good to me - should we bother with an update test?

Writing tests is not my strong suit so I won't probably spend the time, but feel free if you want to.