PhabricatorFulltextToken::isQueryable(), PhabricatorFulltextToken::setIsShort(), PhabricatorFulltextToken::setIsStopword()
all got introduced in rP3245e74f16bb28ae905f76fcc99d722abc8320ab not to query stopwords or short tokens.
These functions were called in https://we.phorge.it/source/phorge/browse/master/src/applications/search/fulltextstorage/PhabricatorMySQLFulltextStorageEngine.php;faca1deea5b5a21aa936032114e7e1b1ba471884.
That Storage Engine got deleted in rPda0a08a7e13e01d5e34bb0a12706a7b4f9e348d6 to move to Ferret; see https://web.archive.org/web/20250422194147/http://secure.phabricator.com/T12819.
Phorge's Elasticsearch related classes do not use such functionality either.
Thus delete these functions, assuming that no third-party StorageEngine calls them in some unknown custom code.