Core: Fix weights file data not being reused

[alwaysintreble]

What is this fixing or adding?

#3380

i forgot about weighted files when i added that delete line apparently. this reverses that checking by just adding the actual valid options to the set instead of deleting weights that we decide are valid.

How was this tested?

generated with 1 custom and a weights file confirming that invalid options still print and custom options from the weights all worked.

[ScipioWright]

Fixed the issue I was having, tested with a TextChoice

[NewSoupVi]

In roll_linked_settings, we make a deepcopy of weights and return it.

In roll_triggers, we make a deepcopy of weights and return it.

In the main function, we don't. So if the yaml has linked options or triggers, we're working with a deep copy, but if it doesn't, we're not.

This might be why some yamls were unaffected in the big async. It's the ones making use of triggers, which "saved" them from being modified. (Edit: This seems to be confirmed)

That seems wacky and error prone. Maybe we should just always make a deepcopy at the start?
I guess it's fine as lone as every time we modify, we make a copy first, and that would be more efficient. But that behavior has to be known

[NewSoupVi]

After thinking about it, I think I would like it if we could either

1. always make a deepcopy, at the very start of the roll_settings function
2. make a function docstring for roll_settings that includes a note along the lines of "The same weights object may be shared by multiple players, so it should not be modified without making a copy first"

[NewSoupVi]

Change works. I have some thoughts about whether it is the correct change & whether there should be some protection against this in the future (pls read my comments above), but it's probably a bit too sensitive of an issue to discuss forever.

[alwaysintreble]

We never deleted the cache previously so I don't think doing so is a good idea when it can be avoided, I just apparently didn't consider this solution when I wrote the original code. Even if we created a deep copy every time I wouldn't trust being able to delete it.