Remove `require 'io/wait'` where it's no longer necessary. (#6932)

* Remove `require 'io/wait'` as it's part of core now.

* Update ruby specs using version gates.

* Add note about why it's conditional.

1 files changed, 5 insertions, 1 deletions

diff --git a/ext/socket/lib/socket.rb b/ext/socket/lib/socket.rb
index 1c091650ff..eecdc7d4b8 100644
--- a/ext/socket/lib/socket.rb
+++ b/ext/socket/lib/socket.rb
@@ -1,7 +1,11 @@
 # frozen_string_literal: true
 
 require 'socket.so'
-require 'io/wait' unless ::IO.method_defined?(:wait_readable, false)
+
+unless IO.method_defined?(:wait_writable, false)
+  # It's only required on older Rubies < v3.2:
+  require 'io/wait'
+end
 
 class Addrinfo
   # creates an Addrinfo object from the arguments.