style: Fix unnecessary-comprehension (C416)

[echoix]

Ruff rule: https://docs.astral.sh/ruff/rules/unnecessary-comprehension/

[ninsbl]

I have not build and tested, but the changes are according to the ruff rule. In some cases I am not sure if the list() is even necessary...

[echoix]

I have not build and tested, but the changes are according to the ruff rule. In some cases I am not sure if the list() is even necessary...

I also researched a bit on the behavior as I thought it helped with copies and the likes. It seems it doesn't help, and is no more different as a shallow copy either. So the list constructor provides the same as the comprehension, only that the list comprehensions are not the fastest.
See these SO questions/answers for example:

• https://stackoverflow.com/q/2612802
• https://stackoverflow.com/a/77224873

It was harder to find real definitive answers that weren't related to Python 2 era.

So, in order to at least have the same behavior, in case there were some edge cases when there wasn't a list (ie, we wouldn't want to have a string not as a list element, as iterating it would go character-per-character instead), using the list constructor seems the best approach.

[echoix]

There was a recursion problem here since __len__ used len(self.mapsets()) and mapsets() was changed too. So I'm adding a # noqa exclusion here. We'll see if it's enough. It isn't obvious why the list constructor used the len() instead of using up the iterable.