Chore: fix separateRequires tests for one-var rule

[mdjermanovic]

What is the purpose of this pull request? (put an "X" next to item)

[X] Other, please explain:

Some tests for the separateRequires option of the one-var rule had this:

parserOptions: { env: { node: true } }

These are incorrect settings because env shouldn't be in parserOptions. It's just ignored as an unknown parser option.

What changes did you make? (Give an overview)

Since the tests are passing without the node environment being actually set, I wasn't sure if the rule was working as intended. In particular, should the option apply to global require or any require call.

By #9441, in particular this thread and this comment it seems that the rule wasn't supposed to check if the require reference is global, so instead of fixing env I just removed these.

Is there anything you'd like reviewers to focus on?

One test became a duplicate, so it's completely removed.

[kaicataldo]

LGTM, thanks!