Investigate dead links from auckland_museum DAG

[stacimc]

Problem

As noted in this comment, many of the results that we ingest from Auckland War Memorial Museum Tāmaki Paenga Hira show either "Server error" or "Online image not available" for the main image file.

These examples were found by @obulat:

"Online image not available" placeholder

https://api.aucklandmuseum.com/id/media/v/3191, https://api.aucklandmuseum.com/id/media/v/2882,

Internal server error

https://api.aucklandmuseum.com/id/media/v/861840
https://api.aucklandmuseum.com/id/media/v/528116
https://api.aucklandmuseum.com/id/media/v/828322
https://api.aucklandmuseum.com/id/media/v/229298

No image on the landing page

https://www.aucklandmuseum.com/collections-research/collections/record/am_humanhistory-object-9923

Placeholder image on the landing page

https://www.aucklandmuseum.com/collections-research/collections/record/am_naturalsciences-object-368805

Description

We should investigate the URLs being returned and ensure that we do not add a large number of deadlinks to the catalog. We should consider getting in touch with the museum to clarify the intention behind results (which are potentially temporary access issues, vs results whose public access has been intentionally removed for cultural sensitivity reasons, and which we therefore do not want to index).

The DAG should be updated to exclude results we don't want to index, once this has been determined. Note that the DAG is not being enabled until this issue is resolved.

Additional context

Read the discussion on #3258, starting around this comment, for more context.