Use released version of websocket-client-simple

It was originally done in rails#26714
but I'm pretty sure this has long since been fixed in ruby itself with ruby/ruby@bc855ef

I also removed some code related to warnings relevant only on Ruby <= 2.7

Author: Earlopain

Gemfile

@@ -117,7 +117,7 @@ group :cable do
 
   gem "redis-namespace"
 
-  gem "websocket-client-simple", github: "matthewd/websocket-client-simple", branch: "close-race", require: false
+  gem "websocket-client-simple", require: false
 end
 
 # Active Storage

Gemfile.lock

@@ -1,12 +1,3 @@
-GIT
-  remote: https://github.com/matthewd/websocket-client-simple.git
-  revision: e161305f1a466b9398d86df3b1731b03362da91b
-  branch: close-race
-  specs:
-    websocket-client-simple (0.3.0)
-      event_emitter
-      websocket
-
 GIT
   remote: https://github.com/nahi/httpclient.git
   revision: d57cc6d5ffee1b566b5c189fe6dc8cc89570b812
@@ -660,6 +651,9 @@ GEM
       hashdiff (>= 0.4.0, < 2.0.0)
     webrick (1.8.2)
     websocket (1.2.11)
+    websocket-client-simple (0.8.0)
+      event_emitter
+      websocket
     websocket-driver (0.7.6)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
@@ -757,7 +751,7 @@ DEPENDENCIES
   web-console
   webmock
   webrick
-  websocket-client-simple!
+  websocket-client-simple
 
 BUNDLED WITH
    2.5.16

actioncable/test/client_test.rb

@@ -8,24 +8,6 @@
 
 require "active_support/hash_with_indifferent_access"
 
-####
-# 😷 Warning suppression 😷
-WebSocket::Frame::Handler::Handler03.prepend Module.new {
-  def initialize(*)
-    @application_data_buffer = nil
-    super
-  end
-}
-
-WebSocket::Frame::Data.prepend Module.new {
-  def initialize(*)
-    @masking_key = nil
-    super
-  end
-}
-#
-####
-
 class ClientTest < ActionCable::TestCase
   WAIT_WHEN_EXPECTING_EVENT = 2
   WAIT_WHEN_NOT_EXPECTING_EVENT = 0.5