What is the ruling on working in a hotel that serves alcohol, knowing that my work as a computer engineer is unrelated to it, and that the hotel owner asserts that the salary does not include profits from alcohol but is allocated for disasters and charities, and given that there is a previous fatwa permitting it and that I have no other source of income?

If your work in the hotel does not involve alcoholic beverages and does not assist in their sale, then there is no sin upon you in it, and your salary is lawful. The fact that the hotel's money is mixed with money from alcohol does not affect the permissibility of the work or the salary. The hotel owner must stop selling alcohol, and the fact that he disposes of its proceeds in charitable ways does not make it permissible for him to continue selling it.