setup: remove msgpack version dependency

DifferentialOrange · DifferentialOrange · commit bd418b08c435 · 2022-10-31T11:57:44.000+03:00
The only reason of this dependency is various vulnerability fixes. We decided not to enforce the user on this. Follows #223, part of #198
diff --git a/requirements.txt b/requirements.txt
@@ -1,4 +1,4 @@
-msgpack>=1.0.4
+msgpack
 pandas
 pytz
 dataclasses; python_version <= '3.6'
