Do not use pthread_setaffinity_np on s390x

Looks like it randomly causes a segfault

https://rubyci.s3.amazonaws.com/rhel_zlinux/ruby-master/log/20231025T093302Z.fail.html.gz
```
[11186/26148] TestNetHTTP_v1_2#test_set_form/home/chkbuild/build/20231025T093302Z/ruby/tool/lib/webrick/httprequest.rb:197: [BUG] Segmentation fault at 0x000003ff1ffff000
ruby 3.3.0dev (2023-10-25T07:50:00Z master 526292d9fe) [s390x-linux]
```

ext/socket/raddrinfo.c

@@ -482,7 +482,10 @@ start:
     }
 
     pthread_detach(th);
-#if defined(HAVE_PTHREAD_SETAFFINITY_NP) && defined(HAVE_SCHED_GETCPU)
+#if defined(__s390__) || defined(__s390x__) || defined(__zarch__) || defined(__SYSC_ZARCH__)
+# define S390X
+#endif
+#if defined(HAVE_PTHREAD_SETAFFINITY_NP) && defined(HAVE_SCHED_GETCPU) && !defined(S390X)
     cpu_set_t tmp_cpu_set;
     CPU_ZERO(&tmp_cpu_set);
     CPU_SET(sched_getcpu(), &tmp_cpu_set);
@@ -701,7 +704,7 @@ start:
     }
 
     pthread_detach(th);
-#if defined(HAVE_PTHREAD_SETAFFINITY_NP) && defined(HAVE_SCHED_GETCPU)
+#if defined(HAVE_PTHREAD_SETAFFINITY_NP) && defined(HAVE_SCHED_GETCPU) && !defined(S390X)
     cpu_set_t tmp_cpu_set;
     CPU_ZERO(&tmp_cpu_set);
     CPU_SET(sched_getcpu(), &tmp_cpu_set);