Function settrace

crates/vm/src/stdlib/sys.rs:1374–1377

(tracefunc: PyObjectRef, vm: &VirtualMachine)

    #[pyfunction]
    fn settrace(tracefunc: PyObjectRef, vm: &VirtualMachine) {
        vm.trace_func.replace(tracefunc);
        update_use_tracing(vm);
    }

    #[pyfunction]
    fn _settraceallthreads(tracefunc: PyObjectRef, vm: &VirtualMachine) {