docs: empty version picker on some pages

  • Version: 8.5.0
  • Platform: n/a
  • Subsystem: n/a

The version picker I added to the docs recently does not properly account for pages without the <-- introduced_in --> tag, or pages with the tag but without multiple version of the doc. The n-api docs are a good example of this. The version drop down is there, but has no options when you click on it.

Affected pages: async_hooks, n-api, deprecations, esm, http2, inspector, intl, perf_hooks, tracing

I already started working on a fix for this and will open a pr later tonight.