remove some maintainerships

I'm no longer using any of these packages, and they're tricky to test
outside a useful context.

pkgs/applications/networking/irc/weechat/default.nix

@@ -85,7 +85,7 @@ let
           on https://nixos.org/nixpkgs/manual/#sec-weechat .
         '';
         license = lib.licenses.gpl3;
-        maintainers = with lib.maintainers; [ lovek323 lheckemann ];
+        maintainers = with lib.maintainers; [ lovek323 ];
         platforms = lib.platforms.unix;
       };
     }

pkgs/applications/networking/opsdroid/default.nix

@@ -29,7 +29,7 @@ python3Packages.buildPythonPackage rec {
   meta = with lib; {
     description = "An open source chat-ops bot framework";
     homepage = "https://opsdroid.dev";
-    maintainers = with maintainers; [ fpletz globin willibutz lheckemann ];
+    maintainers = with maintainers; [ fpletz globin willibutz ];
     license = licenses.asl20;
     platforms = platforms.unix;
   };

pkgs/development/python-modules/ibm-cloud-sdk-core/default.nix

@@ -59,6 +59,6 @@ buildPythonPackage rec {
     description = "Client library for the IBM Cloud services";
     homepage = "https://github.com/IBM/python-sdk-core";
     license = licenses.asl20;
-    maintainers = with maintainers; [ globin lheckemann ];
+    maintainers = with maintainers; [ globin ];
   };
 }

pkgs/development/python-modules/ibm-watson/default.nix

@@ -55,6 +55,6 @@ buildPythonPackage rec {
     description = "Client library to use the IBM Watson Services";
     homepage = "https://github.com/watson-developer-cloud/python-sdk";
     license = licenses.asl20;
-    maintainers = with maintainers; [ globin lheckemann ];
+    maintainers = with maintainers; [ globin ];
   };
 }

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

@@ -28,6 +28,6 @@ buildPythonPackage rec {
     description = "A Python Mattermost Driver";
     homepage = "https://github.com/Vaelor/python-mattermost-driver";
     license = licenses.mit;
-    maintainers = with maintainers; [ globin lheckemann ];
+    maintainers = with maintainers; [ globin ];
   };
 }

pkgs/tools/bluetooth/bluez-alsa/default.nix

@@ -62,7 +62,7 @@ stdenv.mkDerivation rec {
     homepage = src.meta.homepage;
     license = licenses.mit;
     platforms = platforms.linux;
-    maintainers = [ maintainers.oxij maintainers.lheckemann ];
+    maintainers = [ maintainers.oxij ];
   };
 
 }