Search page facet bar(s): element IDs are duplicated

Currently there are many (54) duplicate IDs on a search page. These each count as an error with the automated A11y tools.
(https://127.0.0.1:5000/search?q=&l=list&p=1&s=10&sort=newest)

I think it is because the facet panel is duplicated... one for narrow screens, one for full-width.

Apparently even though one of the panels is always hidden, it still gets included in the scan.

Conversation about it here: https://github.com/dequelabs/axe-core/issues/3363