[Bug]: upgrading an 'assisting' factory, and cancelling the assist order, resets progress on the upgrade

### Describe the Bug

I'm not sure this is a bug, this may be intended behaviour, but it doesn't 'feel' correct.

You have two factories, Factory A, set to assist Factory B. Start upgrading Factory A. At some point in the progress of the upgrade, remove the Assist order from Factory B. The progress on the upgrade of factory A is reset to 0, and progress begins again.

You can see this happening in this 2min replay : - https://replay.faforever.com/25116797

### Reproduce the bug

1. Factory A, set to assist Factory B.
2. Start upgrading Factory A.
3. At some point in the progress of the upgrade, remove the Assist order from Factory B.
4. The progress on the upgrade of factory A is reset to 0, and progress begins again.

### Screenshots

_No response_

### Additional context

I don't think this is limited to any one faction or factory, I've noticed it a number of times in different games.