DEV: skip two flakey specs (#24965)

plugins/chat/spec/system/navigation_spec.rb

@@ -168,6 +168,8 @@ RSpec.describe "Navigation", type: :system do
           before { Fabricate(:chat_message, thread: thread_2, use_service: true) }
 
           it "goes back to the thread list when clicking the back button", mobile: true do
+            skip("Flaky on CI") if ENV["CI"]
+
             chat_page.visit_channel(category_channel)
             channel_page.message_thread_indicator(thread.original_message).click
             thread_page.send_message

plugins/chat/spec/system/thread_tracking/drawer_spec.rb

@@ -44,6 +44,8 @@ describe "Thread tracking state | drawer", type: :system do
     end
 
     it "marks the thread as read and removes both indicators when the user opens it" do
+      skip("Flaky on CI") if ENV["CI"]
+
       visit("/")
       chat_page.open_from_header
       drawer_page.open_channel(channel)