fix(data): backfill invites where missing user can be linked

Co-authored-by: Colin Darie <colin@darie.eu>

lib/tasks/deployment/20231226140149_backfill_invites_missing_existing_user.rake

@@ -0,0 +1,22 @@
+namespace :after_party do
+  desc 'Deployment task: backfill_invites_missing_existing_user'
+  task backfill_invites_missing_existing_user: :environment do
+    puts "Running deploy task 'backfill_invites_missing_existing_user'"
+
+    # Put your task implementation HERE.
+    Invite.where.missing(:user).in_batches do |invites_with_missing_user|
+      linkable_users_and_invite = User.where(email: invites_with_missing_user.pluck(:email))
+      linkable_users_and_invite.each do |linkable_user_and_invite|
+        begin
+          linkable_user_and_invite.after_confirmation # calls link_invites!
+        rescue err
+          Sentry.capture_exception(err)
+        end
+      end
+    end
+    # Update task as completed.  If you remove the line below, the task will
+    # run with every deploy (or every time you call after_party:run).
+    AfterParty::TaskRecord
+      .create version: AfterParty::TaskRecorder.new(__FILE__).timestamp
+  end
+end