Ok, so creating only one DAO it’s just as simply as putting everything together in one class ;) So your DAO will look like this:

@Dao
public interface ModelDao {

    @Insert
    void insert(User user);

    @Query("SELECT * FROM user")
    List<User> getAllUsers();

    @Insert
    void insert(Repo user);

    @Query("SELECT * FROM repo")
    List<Repo> getAllReopsitories();
}

And your database class will have only this one DAO:

@Database(entities = { User.class, Repo.class, Issue.class }, version = 1)
public abstract class RepoDatabase extends RoomDatabase {

    ...

    public abstract ModelDao getModelDao();
}

However, I still want to highlight that I don’t recommend this approach. Does it help you?