x11-wm/compton-yshui: unbreak build with GCC

In file included from ../subprojects/test.h/test.h:14,

from ../src/string_utils.c:6:

/usr/include/sys/sysctl.h:1101:25: error: unknown type name 'u_int'; did you mean 'int'?
1101 | int sysctl(const int *, u_int, void *, size_t *, const void *, size_t);

|                         ^~~~~
|                         int

PR: 241724
Submitted by: pkubaj
Obtained from: upstream