treewide: remove alxsimon as maintainer (#434934)

Alexis Simon has requested to drop their maintainership of several python packages.

maintainers/maintainer-list.nix

···
     githubId = 373;
     name = "Alexandre Girard Davila";
   };
-  alxsimon = {
-    email = "[e-mail]";
-    github = "alxsimon";
-    githubId = 9567176;
-    name = "Alexis Simon";
-  };
   amadaluzia = {
     email = "[e-mail]";
     github = "amadaluzia";

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

···
     mainProgram = "demes";
     homepage = "https://github.com/popsim-consortium/demes-python";
     license = licenses.isc;
-    maintainers = with maintainers; [ alxsimon ];
+    maintainers = with maintainers; [ ];
   };
 }

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

···
     mainProgram = "demesdraw";
     homepage = "https://github.com/grahamgower/demesdraw";
     license = licenses.isc;
-    maintainers = with maintainers; [ alxsimon ];
+    maintainers = with maintainers; [ ];
   };
 }

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

···
     homepage = "https://github.com/tskit-dev/msprime";
     changelog = "https://github.com/tskit-dev/msprime/blob/${version}/CHANGELOG.md";
     license = licenses.gpl3Plus;
-    maintainers = with maintainers; [ alxsimon ];
+    maintainers = with maintainers; [ ];
   };
 }

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

···
     description = "Python package to read and write the Newick format";
     homepage = "https://github.com/dlce-eva/python-newick";
     license = licenses.asl20;
-    maintainers = with maintainers; [ alxsimon ];
+    maintainers = with maintainers; [ ];
   };
 }

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

···
     description = "Tools for dealing with tree sequences coming to and from SLiM";
     homepage = "https://github.com/tskit-dev/pyslim";
     license = licenses.mit;
-    maintainers = with maintainers; [ alxsimon ];
+    maintainers = with maintainers; [ ];
   };
 }

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

···
     mainProgram = "tskit";
     homepage = "https://github.com/tskit-dev/tskit";
     license = lib.licenses.mit;
-    maintainers = with lib.maintainers; [ alxsimon ];
+    maintainers = with lib.maintainers; [ ];
   };
 }