What is the ruling on working and tax evasion in a non-Islamic country in exchange for social services provided by the state, and is it permissible if the government spends some of its money on unlawful things?

A Muslim must fulfill the permissible conditions he committed to in the residency contract, and this includes paying the taxes he committed to in exchange for being permitted to work. The fact that the government might spend some of its money on what is forbidden does not permit deception and trickery regarding the permissible conditions, nor does his payment of money constitute forbidden assistance.