python: get rid of msgpack-python, fixes #48864

We already have msgpack, which is the same. Building a Python env with
`spacy` resulted in a collision between an `.so` provided through both
`msgpack` and `msgpack-python`.

I don't know why `transitional = True` was set. These kind of things
should be documented!

pkgs/development/python-modules/intake/default.nix

@@ -7,7 +7,7 @@
 , hvplot
 , jinja2
 , msgpack-numpy
-, msgpack-python
+, msgpack
 , numpy
 , pandas
 , panel
@@ -39,7 +39,7 @@ buildPythonPackage rec {
     hvplot
     jinja2
     msgpack-numpy
-    msgpack-python
+    msgpack
     numpy
     pandas
     panel