Step ignored when same steps are defined in the same version

[grindtildeath]

Context :
When there are multiple same steps defined for the same version, the first one is ignored.

Example :

version v.w.x.y.z:
operations:
  pre:
    - anthem songs.script_pre::main
addons:
  update:
    - my_beautiful_module
operations:
  post:
    - anthem songs.script_post::main

With such a migration step, running version v.w.x.y.z will only execute anthem songs.script_post::main as post and won't execute anthem songs.script_pre::main ! ⚠️

IMO in such cases marabunta must raise an error instead of ignoring a script, leaving the user wondering why his script was not executed.