message: remove duplicated adding to the cache
diff: @@ -1096,31 +1096,17 @@ fn activate_deps_loop(
  }
  }
  if !has_another && has_past_conflicting_dep && !backtracked {
  - // we have not activated ANY candidates and
  - // we are out of choices so add it to the cache
  - // so our parent will know that we don't work
  - let past = past_conflicting_activations
  - .entry(dep.clone())
  - .or_insert_with(Vec::new);
  - if !past.contains(&conflicting_activations) {
  - trace!(
  - "{}[{}]>{} adding a meta-skip {:?}",
  - parent.name(),
  - cur,
  - dep.name(),
  - conflicting_activations
  - );
  - past.push(conflicting_activations.clone());
  - // also clean the `backtrack_stack` so we don't
  + // we have not activated ANY candidates.
  + // So clean the `backtrack_stack` so we don't
  // backtrack to a place where we will try this again.
  backtrack_stack.retain(|bframe| {
  + // Maybe we could just not add them in the first place, but for now this works
  !bframe.context_backup.is_conflicting(
  Some(parent.package_id()),
  &conflicting_activations,
  )
  });
  }
  - }
  // if not has_another we we activate for the better error messages
  frame.just_for_error_messages = has_past_conflicting_dep;
  if !has_past_conflicting_dep
  