Clean hub tags

[mikkelhegn]

Fix #1354

[itowlson]

CI failures are spurious and fixed in another PR

[mikkelhegn]

@itowlson - I struggled a bit with this, so wanted to be sure we're on the same page here. These are the tags shown on the cards, and are not what's use for filtering (through the left hand-side menu).

These are part of the search index, together with keywords and tags (which are the left-hand filters).

I think there's a consolidation potential to not have both tags and keywords, but just one of them. I'll link this PR to this issue to track that: #862

[itowlson]

Yes, that is my understanding, and I agree that we should review whether the separation is useful. The fact that you can't click on tags, and that tags don't contribute to search, is surprising to me. But that's definitely a separate issue (and thanks for raising something to track it).