Fix invalid return from some _get/_set

[AThousandShips]

Invalidly returned true on the non-matched path, these do not break anything by blocking inherited properties, at least not right now

There are some remaining cases for Skeleton and SkeletonModification*, but they are a bit more complicated so not touching them right now, these were the trivial cases

• Fixes: if "string" in ArrayMesh—Always returns true #84041

[AThousandShips]

Given the very varying style and format of the _get/_set methods across the codebase I might look at unifying them at some point, they follow a number of different styles of handling different paths and it's error prone to modify them

[YuriSizov]

This seems fine. Would appreciate the @godotengine/animation team to confirm that there is no required magic going on with those (if there is, we ought to add comments about that, not just leave it as is).

[AThousandShips]

if there is, we ought to add comments about that, not just leave it as is

Indeed, will go over the animation cases later and open a PR for them but they require a bit more work, and will add comments there otherwise if there's some reason

Edit: Was checking if the 3.x version also needed fixing but it appears it has a very different code for these cases, and looks like the error snuck in with the refactoring of it

[akien-mga]

Thanks!

[AThousandShips]

Thank you!

[donn-xx]

Magic!

[YuriSizov]

Cherry-picked for 4.1.4.