Transmogrifier: handle non-validate errors on incoming Delete activities

This should fix WithClauseError resulting in Oban jobs for processing
incoming deletes being retried without getting cancelled when those
deletes are MRF rejected.

changelog.d/handle-non-validate-delete-errors.change

@@ -0,0 +1 @@
+Transmogrifier: handle non-validate errors on incoming Delete activities

lib/pleroma/web/activity_pub/transmogrifier.ex

@@ -530,6 +530,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
         else
           _ -> e
         end
+      e -> {:error, e}
     end
   end