LONDON — Five Bulgarian nationals accused of working as part of a Russian spy ring in the U.K. will go on trial next year, a judge at the Old Bailey court ruled Friday. Vanya Gaberova, 29, Orlin Roussev, 45, Bizer Dzhambazov, 41, Katrin Ivanova, 32, and Ivan Stoyanov, 31, are charged with conspiracy to collect information that may be useful to a foreign power between Aug. 30, 2020, and Feb. 8, 2023. The defendants appeared by video link from prison. Dzhambazov and Ivanova, a couple living at the same North London address, and Roussev, arrested in a three-star hotel in the seaside town of Great Yarmouth, face the additional charge of possessing false identity documents.