chore(eslint): Enable and auto-fix prefer-array-index-of

[ryan953]

No description provided.

[ryan953]

There's a type error here i didn't dig into, the type of token is huge.

That the types don't match might indicate an (existing?) problem

[billyvg]

Is there a functional difference between these two or is it more stylistic? Contrast this to #88049 where it's objectively + functionally better (and subjectively, stylistically better imo)

[ryan953]

Is there a functional difference between these two or is it more stylistic? Contrast this to #88049 where it's objectively + functionally better (and subjectively, stylistically better imo)

They should be functionally the same. The changes were made but an auto-fix rule, so i put some trust in that when i chose to turn this on.

The docs for each method are here:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findIndex
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf

I'll call out that indexOf uses the same algorithm used by the === operator which all of the changes in this PR were already using.

I think in terms of types TS is doing a better job now, which is why I stomped on some violations that popped up.