Don't log when users or objects are deleted.

lib/pleroma/object/fetcher.ex

@@ -117,6 +117,9 @@ def fetch_object_from_id!(id, options \\ []) do
       {:error, %Tesla.Mock.Error{}} ->
         nil
 
+      {:error, "Object has been deleted"} ->
+        nil
+
       e ->
         Logger.error("Error while fetching #{id}: #{inspect(e)}")
         nil

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -1377,6 +1377,10 @@ def fetch_and_prepare_user_from_ap_id(ap_id) do
          data <- maybe_update_follow_information(data) do
       {:ok, data}
     else
+      {:error, "Object has been deleted"} = e ->
+        Logger.debug("Could not decode user at fetch #{ap_id}, #{inspect(e)}")
+        {:error, e}
+
       e ->
         Logger.error("Could not decode user at fetch #{ap_id}, #{inspect(e)}")
         {:error, e}