For instances without ElasticSearch, we currently still offer a search based on the wb_terms table and its term_search_key column. Remove that – wikis without ElasticSearch will only have limited search support where the search term must be an exact prefix of the label/alias, with no case folding or normalization. (Strictly speaking, this will no longer be supported as soon as we remove the configuration options – T264278 – so this task is mostly about removing the related code.)

Acceptance criteria:

• The wiring code for search service creation using the old term index is removed
• Any unused (after this) classes are removed