Wait longer for mirror update

Given that mirroring is a background process that can take time to be
scheduled in shared environments, this makes tests wait up to 3
minutes for an update.

qa/qa/page/project/settings/mirroring_repositories.rb

@@ -98,7 +98,7 @@ module QA
             sleep 5
             refresh
 
-            wait_until(sleep_interval: 1) do
+            wait_until(max_duration: 180, sleep_interval: 1) do
               within_element_by_index(:mirrored_repository_row, row_index) do
                 last_update = find_element(:mirror_last_update_at_cell, wait: 0)
                 last_update.has_text?('just now') || last_update.has_text?('seconds')