fix(transfer): remove discarded dossiers from transfers

app/models/dossier.rb

@@ -678,6 +678,7 @@ class Dossier < ApplicationRecord
       end
     end
 
+    update!(dossier_transfer_id: nil)
     discard!
   end
 

app/models/dossier_transfer.rb

@@ -37,7 +37,7 @@ class DossierTransfer < ApplicationRecord
         }
       end)
       transfer.dossiers.update_all(user_id: current_user.id)
-      transfer.destroy
+      transfer.destroy_and_nullify
     end
   end
 
@@ -48,7 +48,7 @@ class DossierTransfer < ApplicationRecord
   def destroy_and_nullify
     transaction do
       # Rails cascading is not working with default scopes. Doing nullify cascade manually.
-      Dossier.with_discarded.where(transfer: self).update_all(dossier_transfer_id: nil)
+      dossiers.with_discarded.update_all(dossier_transfer_id: nil)
       destroy
     end
   end

app/models/user.rb

@@ -191,7 +191,7 @@ class User < ApplicationRecord
       .where.not(operation: DossierOperationLog.operations.fetch(:supprimer))
       .destroy_all
     dossiers.with_discarded.discarded.destroy_all
-    dossiers.update_all(deleted_user_email_never_send: email, user_id: nil)
+    dossiers.update_all(deleted_user_email_never_send: email, user_id: nil, dossier_transfer_id: nil)
     destroy!
   end