remove autoconf check for select() (#3283)

We never actually check HAVE_SELECT.

configure

@@ -11328,7 +11328,7 @@ for ac_func in alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
  mkfifoat mknod mknodat mktime mremap nice openat pathconf pause pipe2 plock poll \
  posix_fallocate posix_fadvise pread \
  pthread_init pthread_kill putenv pwrite readlink readlinkat readv realpath renameat \
- select sem_open sem_timedwait sem_getvalue sem_unlink sendfile setegid seteuid \
+ sem_open sem_timedwait sem_getvalue sem_unlink sendfile setegid seteuid \
  setgid sethostname \
  setlocale setregid setreuid setresuid setresgid setsid setpgid setpgrp setpriority setuid setvbuf \
  sched_get_priority_max sched_setaffinity sched_setscheduler sched_setparam \

configure.ac

@@ -3485,7 +3485,7 @@ AC_CHECK_FUNCS(alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
  mkfifoat mknod mknodat mktime mremap nice openat pathconf pause pipe2 plock poll \
  posix_fallocate posix_fadvise pread \
  pthread_init pthread_kill putenv pwrite readlink readlinkat readv realpath renameat \
- select sem_open sem_timedwait sem_getvalue sem_unlink sendfile setegid seteuid \
+ sem_open sem_timedwait sem_getvalue sem_unlink sendfile setegid seteuid \
  setgid sethostname \
  setlocale setregid setreuid setresuid setresgid setsid setpgid setpgrp setpriority setuid setvbuf \
  sched_get_priority_max sched_setaffinity sched_setscheduler sched_setparam \

pyconfig.h.in

@@ -775,9 +775,6 @@
 /* Define to 1 if you have the `sched_setscheduler' function. */
 #undef HAVE_SCHED_SETSCHEDULER
 
-/* Define to 1 if you have the `select' function. */
-#undef HAVE_SELECT
-
 /* Define to 1 if you have the `sem_getvalue' function. */
 #undef HAVE_SEM_GETVALUE