Change public thread view to hide "Show thread" link (#15266)

Fixes #15262

app/views/statuses/_simple_status.html.haml

@@ -1,3 +1,6 @@
+:ruby
+  hide_show_thread ||= false
+
 .status{ class: "status-#{status.visibility}" }
   .status__info
     = link_to ActivityPub::TagManager.instance.url_for(status), class: 'status__relative-time u-url u-uid', target: stream_link_target, rel: 'noopener noreferrer' do
@@ -47,7 +50,7 @@
   - elsif status.preview_card
     = react_component :card, sensitive: sensitized?(status, current_account), 'maxDescription': 160, card: ActiveModelSerializers::SerializableResource.new(status.preview_card, serializer: REST::PreviewCardSerializer).as_json
 
-  - if !status.in_reply_to_id.nil? && status.in_reply_to_account_id == status.account.id
+  - if !status.in_reply_to_id.nil? && status.in_reply_to_account_id == status.account.id && !hide_show_thread
     = link_to ActivityPub::TagManager.instance.url_for(status), class: 'status__content__read-more-button', target: stream_link_target, rel: 'noopener noreferrer' do
       = t 'statuses.show_thread'
 

app/views/statuses/_status.html.haml

@@ -39,7 +39,7 @@
       %span
         = t('stream_entries.pinned')
 
-  = render (centered ? 'statuses/detailed_status' : 'statuses/simple_status'), status: status.proper, autoplay: autoplay
+  = render (centered ? 'statuses/detailed_status' : 'statuses/simple_status'), status: status.proper, autoplay: autoplay, hide_show_thread: is_predecessor || is_successor
 
 - if include_threads
   - if @since_descendant_thread_id