Remove unused parts of strip-comments

Going through this made it obvious just how little of strip-comments we actually use.

We should expand our tests a little (since we're implicitly relying on a bunch of tests in https://github.com/jonschlinkert/strip-comments that we don't run) and remove everything we don't need, but I'll do that in another PR.

_Originally posted by @ojeytonwilliams in https://github.com/freeCodeCamp/curriculum-helpers/issues/120#issuecomment-1907906065_

Locate the local strip-comments implementation and its existing tests, then compare the covered behavior with the upstream jonschlinkert/strip-comments tests linked in the issue. Expand coverage for the behavior the package actually relies on and remove unused parts; done means the relevant tests pass without retaining unsupported functionality.

Written by the indexing model from the issue text.