Remove some synonyms
Remove some synonyms

The addition of these synonyms coincided with a drop in click-through-rates and
NDCG. We are removing these to see whether search quality improves.

Generally spelling errors should be solved with fuzzy search features rather than
synonyms.

This partially reverts "Add new synonyms for misspellings and refining COVID-19 synonyms"

This partially reverts commit 410cf3cb42cf616db595212e0247d0d13991ee55.

alphagov/rummager,alphagov/rummager