This is just a cat and mouse game with cheat developers. You can’t design software that is perfectly able to determine that is only running in an unmodified environment. This is a form of the halting problem; any software check you do could be faked.

Windows anti cheat gets around this by using code signing and Trusted Platform Modules, which Linux would never be able to support without Linux users giving up control of their own operating system, which is not something a Linux user would do.