Update resource limit handling

This commit aligns snippet tag's resource
limit handling with assign tag's `assign_score_of`
method where the snippet variable acts as a pointer
to a block body - increasing assign score by one

lib/liquid/tags/snippet.rb

@@ -28,18 +28,12 @@ module Liquid
     def render_to_output_buffer(context, output)
       snippet_drop = SnippetDrop.new(@body, @to, context.template_name)
       context.scopes.last[@to] = snippet_drop
-      context.resource_limits.increment_assign_score(assign_score_of(snippet_drop))
+      context.resource_limits.increment_assign_score(1)
       output
     end
 
     def blank?
       true
     end
-
-    private
-
-    def assign_score_of(snippet_drop)
-      snippet_drop.body.nodelist.sum { |node| node.to_s.bytesize }
-    end
   end
 end