generate_preference_list: Revert Tag table auto incr value

- not reverted by default when ROLLBACK on MariaDB is issued
- resetting to 1 works because DB will still ensure no duplicates occure

server/entertainment_decider/models.py

@@ -416,6 +416,7 @@ def generate_preference_list(
         base = base.adapt_score(first_element, score_adapt)
         element_list = object_gen()
     orm.rollback()
+    db.execute(f"ALTER TABLE {Tag._table_} AUTO_INCREMENT = 1;")
     return [MediaElement[i] for i in res_ids]