python3Packages: provide setuptools-scm with toml[i] by default and remove duplicated toml packages

Some packages seem to still require toml despite setuptools-scm having switched to tomli.
If it is missing the version number in dist.into is set to 0.0.0 and silently all version pins break.

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

@@ -1,6 +1,6 @@
 { lib, buildPythonPackage, fetchPypi, isPy3k
 , six, jaraco_logging, jaraco_text, jaraco_stream, pytz, jaraco_itertools
-, setuptools-scm, jaraco_collections, importlib-metadata, toml
+, setuptools-scm, jaraco_collections, importlib-metadata
 }:
 
 buildPythonPackage rec {
@@ -28,7 +28,6 @@ buildPythonPackage rec {
     pytz
     jaraco_itertools
     jaraco_collections
-    toml
   ];
 
   meta = with lib; {