Make `util.isArray()` EOL

[Renegade334]

util.isArray() was the sole util.is* type-checking method left over from #52744. The remainder are all EOL as of v23.0.0.

It looks like the motivation for leaving this at the time was to allow for its use to be removed from the form-data library, which it has since been.

Is there another motivation for leaving this as-is, or can it now be made EOL?

cc: @marco-ippolito

[anonrig]

Can you open a pull-request?

[marco-ippolito]

I remember there were other libraries affected, we need to run citgm

[miguelmarcondesf]

I can take a look if you want to @Renegade334

[Renegade334]

I can take a look if you want to

Sure, if you fancy.

Could also experiment with running citgm against removing util._extend(), as the other surviving graduate of #50488, although I suspect that legacy debug dependencies will still be an issue there.

[jasnell]

This is one I'm less convinced that we can do. I still encounter a fair number of util.isArray(...) calls in third party dependencies.

[ljharb]

fwiw if it's a small enough list, then like form-data, i could attempt to steward them and maximally backport a change.