treewide: remove myself as maintainer

maintainers/maintainer-list.nix

···
     githubId = 9720532;
     name = "Sergei K";
   };
-  sondr3 = {
-    email = "[e-mail]";
-    github = "sondr3";
-    githubId = 2280539;
-    name = "Sondre Nilsen";
-    keys = [{
-      fingerprint = "0EC3 FA89 EFBA B421 F82E  40B0 2567 6BCB FFAD 76B1";
-    }];
-  };
   sophrosyne = {
     email = "[e-mail]";
     github = "sophrosyne97";

pkgs/applications/version-management/git-and-tools/git-ignore/default.nix

···
     description = "Quickly and easily fetch .gitignore templates from gitignore.io";
     homepage = "https://github.com/sondr3/git-ignore";
     license = licenses.gpl3Plus;
-    maintainers = [ maintainers.sondr3 ];
+    maintainers = [ ];
   };
 }

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

···
   meta = with lib; {
     description = "Python library to simplify working with jsonlines and ndjson data";
     homepage = "https://github.com/wbolster/jsonlines";
-    maintainers = with maintainers; [ sondr3 ];
+    maintainers = with maintainers; [ ];
     license = licenses.bsd3;
   };
 }

pkgs/development/tools/rust/cargo-outdated/default.nix

···
     homepage = "https://github.com/kbknapp/cargo-outdated";
     changelog = "https://github.com/kbknapp/cargo-outdated/blob/${version}/CHANGELOG.md";
     license = with licenses; [ asl20 /* or */ mit ];
-    maintainers = with maintainers; [ sondr3 ivan ];
+    maintainers = with maintainers; [ ivan ];
   };
 }

pkgs/tools/system/jump/default.nix

···
     '';
     homepage = "https://github.com/gsamokovarov/jump";
     license = licenses.mit;
-    maintainers = with maintainers; [ sondr3 ];
+    maintainers = with maintainers; [ ];
   };
 }