wait3 and wait4 typing

[likewei92]

According to python docs, wait3 and wait4 returns a resource usages struct the same as resources.getrusage. The typing for that struct already exists, using it here.
https://docs.python.org/3/library/os.html#os.wait3

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉

[Akuli]

Thanks! These return struct_rusage as expected on my system:

>>> import os
>>> if (child_pid := os.fork()) == 0: os.execvp("sleep", ["sleep", "20"])
... 
>>> os.wait3(0)
(8771, 0, resource.struct_rusage(ru_utime=0.0029389999999999998, ru_stime=0.0, ru_maxrss=9652, ru_ixrss=0, ru_idrss=0, ru_isrss=0, ru_minflt=291, ru_majflt=0, ru_nswap=0, ru_inblock=0, ru_oublock=0, ru_msgsnd=0, ru_msgrcv=0, ru_nsignals=0, ru_nvcsw=2, ru_nivcsw=0))
>>> if (child_pid := os.fork()) == 0: os.execvp("sleep", ["sleep", "20"])
... 
>>> os.wait4(child_pid, 0)
(8787, 0, resource.struct_rusage(ru_utime=0.0, ru_stime=0.002195, ru_maxrss=9840, ru_ixrss=0, ru_idrss=0, ru_isrss=0, ru_minflt=294, ru_majflt=0, ru_nswap=0, ru_inblock=0, ru_oublock=0, ru_msgsnd=0, ru_msgrcv=0, ru_nsignals=0, ru_nvcsw=2, ru_nivcsw=1))