Sorry, looks like the fix will have to come out in v1.6, available in a week or so.

In the meantime you can fix it manually by running this: (change postgres_container to your DB container)

docker exec -i postgres_container psql -U piefed piefed <<'SQL'
ALTER TABLE post_vote
    DROP CONSTRAINT IF EXISTS post_vote_post_id_fkey,
    ADD CONSTRAINT post_vote_post_id_fkey
        FOREIGN KEY (post_id)
        REFERENCES post(id)
        ON DELETE CASCADE;

ALTER TABLE post_reply_vote
    DROP CONSTRAINT IF EXISTS post_reply_vote_post_reply_id_fkey,
    ADD CONSTRAINT post_reply_vote_post_reply_id_fkey
        FOREIGN KEY (post_reply_id)
        REFERENCES post_reply(id)
        ON DELETE CASCADE;
SQL