Import needs to capture deleted bibcodes in ADSCachedExports in the bib_data.identifiers list on a regular basis

[seasidesparrow]

A number of bibcodes appeared in libraries that were not in Solr. Testing revealed that these deleted bibcodes were being exported by ADSExports as additional identifiers for their canonical counterpart, but the deleted bibcodes weren't making it into the Solr record unless the --ignore-json-fingerprints switch was being used.

This may be acceptable for records generally, but we need a mechanism that any additions to the classic file abstracts/config/bibcodes.list.del make it into Solr records. This may necessitate an additional cron task that specifically loads the
canonical bibcodes from that file, and forces a reingest with ADSExports.