Use relation_count to avoid ordered count in has_next_page

[rmosolgo]

Fixes #4911

[rmosolgo]

This is not right. As shown by the test failure, @nodes is already an Array at this point:

graphql-ruby/lib/graphql/pagination/relation_connection.rb

Lines 220 to 225 in b167d08

	# Load nodes after applying first/last/before/after,
	# returns an array of nodes
	def load_nodes
	# Return an array so we can consistently use `.index(node)` on it
	@nodes ||= limited_nodes.to_a
	end