Incorporate updated antora-lunr search once merged there

[oddhack]

Tracking issue for search: @gpx1000 came up with a big improvement which we currently incorporate into our build environment, and someone was kind enough to boost that into an MR in the antora-lunr repo: https://gitlab.com/antora/antora-lunr-extension/-/merge_requests/93 . Once that is merged and published in a package update, we should migrate over to the upstreamed fix and stop using the local one.

[oddhack]

This is deferred pending the antora-lunr PR being merged and an updated package published.

[oddhack]

@gpx1000 note that https://gitlab.com/antora/antora-lunr-extension/-/issues/61 has resolving this issue as the only blocker on an antora-lunr 1.0.0 release. Not sure what they would need to move forward (probably time more than anything else, that has been pending for 8 months). But you might check in on that issue or on https://gitlab.com/antora/antora-lunr-extension/-/merge_requests/93 where the MR exists and see if there's something that would help progress it.

If you are still having trouble with ssh keys and gitlab.com access, I or @khronos2 could likely assist with that. But you could comment with just a gitlab.com login, even if you cannot pull the repository.

[oddhack]

I checked on this - it appears held up partly because the third party MR https://gitlab.com/antora/antora-lunr-extension/-/merge_requests/93 based on @gpx1000's work has fallen out of date. Pinged to see if that could be done, or I could do it instead in a new MR, because accepting that MR unblocks a chain of events that should allow an antora-lunr 1.0 release including these changes.