ingest: Remove strain name extraction

[victorlin]

scripts/extract_from_strain.py is used to extract information from strain names. Specifically with the current data, it extracts a more accurate collection year for 35 samples. The full output can be found in any recent run of Ingest to phylogenetic.

'PP_000N5LB': date '2015-XX-XX' → '2001-XX-XX'
'PP_000N73A': date '2015-XX-XX' → '2001-XX-XX'
'PP_000N748': date '2015-XX-XX' → '2001-XX-XX'
…

All 35 collection date inaccuracies have already been reported in pathoplexus/curation_reports#7. Once Pathoplexus is updated with the corrected dates, it should be safe to remove this script and simplify the workflow.