remove JRuby resolv.rb patch following fix in 9.2.9.0

Fixes #11330

logstash-core/lib/logstash/patches.rb

@@ -4,4 +4,3 @@ require "logstash/patches/cabin"
 require "logstash/patches/profile_require_calls"
 require "logstash/patches/stronger_openssl_defaults"
 require "logstash/patches/exception_to_json"
-require "logstash/patches/resolv"

logstash-core/lib/logstash/patches/resolv.rb

@@ -1,25 +0,0 @@
-require "resolv"
-
-# ref:
-#   https://github.com/logstash-plugins/logstash-filter-dns/issues/51
-#   https://github.com/jruby/jruby/pull/5722
-#
-# JRuby versions starting at 9.2.0.0 have a bug in resolv.rb with a leak between the
-# DNS.allocate_request_id/DNS.free_request_id methods.
-#
-# We are opting to load a patched full resolv.rb instead of monkey patching the
-# offending methods because we do not yet know in which upcoming version of JRuby
-# this will be fixed and we want to avoid potential conflicting monkey patches.
-# A spec which will break on JRuby upgrade will redirect here
-# to make a manual verification and eventually remove that patch here once the fix is
-# made in the JRuby version of resolv.rb.
-
-if Gem::Version.new(JRUBY_VERSION) >= Gem::Version.new("9.2.0.0")
-  # save verbose level and mute the "warning: already initialized constant"
-  warn_level = $VERBOSE
-  $VERBOSE = nil
-
-  require_relative "resolv_9270"
-
-  $VERBOSE = warn_level
-end