ansel: add mbornand as maintainer

maintainers/maintainer-list.nix

···
     githubId = 51356;
     name = "Mathieu Boespflug";
   };
+  mBornand = {
+    email = "[e-mail]";
+    github = "mBornand";
+    githubId = 63592189;
+    name = "Marc Bornand";
+  };
   mbprtpmnr = {
     name = "mbprtpmnr";
     email = "[e-mail]";

pkgs/by-name/an/ansel/package.nix

···
     description = "Darktable fork minus the bloat plus some design vision";
     homepage = "https://ansel.photos/";
     license = lib.licenses.gpl3Plus;
-    maintainers = with lib.maintainers; [ ];
+    maintainers = with lib.maintainers; [ mBornand ];
     mainProgram = "ansel";
     platforms = lib.platforms.linux;
   };