Revert "DEV: Replace Rinku native gem with PrettyText" (#31692)

Reverts discourse/discourse#31557

This is causing excessive spacing due to the addition of empty `<p>`
tags. Revert first while we fix that.

lib/twitter_api.rb

@@ -26,8 +26,7 @@ class TwitterApi
         end
       end
       text = link_hashtags_in link_handles_in text
-      result =
-        PrettyText.cook(text, features_override: []).delete_prefix("<p>").delete_suffix("</p>")
+      result = Rinku.auto_link(text, :all, 'target="_blank"').to_s
 
       if tweet[:includes] && media = tweet[:includes][:media]
         media.each do |m|