Correct usage of Nokogiri::Element.new to pass a document, not a node as the second argument per deprecation notice.

Author: gkellogg

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
         ruby:
           - 2.6
           - 2.7
-          - 3.0
+          - "3.0"
           - 3.1
           - ruby-head
           - jruby

lib/rdf/rdfxml/reader/nokogiri.rb

@@ -25,7 +25,7 @@ def initialize(node, parent = nil)
 
         # Create a new element child of an existing node
         def create_node(name, children)
-          native = ::Nokogiri::XML::Element.new(name, @node)
+          native = ::Nokogiri::XML::Element.new(name, @node.document)
           children.each do |c|
             native.add_child(c.node)
           end