Bring back Registers#each

[isimluk]

Registers#each are being used in the template.rb anyway.

Basically merely passing registers from context to template options crashes liquid version 5.4, while it worked in liquid-5.3.

Addressing:

/opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/liquid-5.4.0/lib/liquid/template.rb:176:in `render': undefined method `each' for #<Liquid::Registers:0x00007f2b142ddfc0>

        options[:registers]&.each do |key, register|
                           ^^^^^^
	from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/liquid-5.4.0/lib/liquid/template.rb:204:in `render!'
	from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/jekyll-seo-tag-2.8.0/lib/jekyll-seo-tag.rb:36:in `render'
	from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/liquid-5.4.0/lib/liquid/tag.rb:51:in `render_to_output_buffer'
	from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/liquid-5.4.0/lib/liquid/block_body.rb:80:in `render_node'
	from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/liquid-5.4.0/lib/liquid/block_body.rb:230:in `render_node'
	from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/liquid-5.4.0/lib/liquid/block_body.rb:213:in `render_to_output_buffer'
	from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/liquid-5.4.0/lib/liquid/document.rb:41:in `render_to_output_buffer'
	from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/liquid-5.4.0/lib/liquid/template.rb:194:in `render'
	from /opt/hostedtoolcache/Ruby/3.1.2/x64/lib/ruby/gems/3.1.0/gems/liquid-5.4.0/lib/liquid/template.rb:204:in `render!'