Remove deprecated `ActionDispatch::Request#deep_munge`

actionpack/CHANGELOG.md

+*   Remove deprecated `ActionDispatch::Request#deep_munge`.
+
+    *Rafael Mendonça França*
+
 *   Remove deprecated `ActionDispatch::Http::Parameters#symbolized_path_parameters`.
 
     *Rafael Mendonça França*

actionpack/lib/action_dispatch/http/request.rb

@@ -337,15 +337,6 @@ def local?
       LOCALHOST =~ remote_addr && LOCALHOST =~ remote_ip
     end
 
-    # Extracted into ActionDispatch::Request::Utils.deep_munge, but kept here for backwards compatibility.
-    def deep_munge(hash)
-      ActiveSupport::Deprecation.warn(
-        'This method has been extracted into `ActionDispatch::Request::Utils.deep_munge`. Please start using that instead.'
-      )
-
-      Utils.deep_munge(hash)
-    end
-
     protected
       def parse_query(qs)
         Utils.deep_munge(super)