treewide: remove lethalman from meta.maintainers

He hasn't been heard of for years.

pkgs/tools/system/netdata/default.nix

@@ -87,6 +87,6 @@ in stdenv.mkDerivation rec {
     homepage = "https://www.netdata.cloud/";
     license = licenses.gpl3Plus;
     platforms = platforms.unix;
-    maintainers = [ maintainers.lethalman ];
+    maintainers = [ ];
   };
 }

pkgs/tools/system/netdata/go.d.plugin.nix

@@ -26,6 +26,6 @@ buildGoModule rec {
     description = "Netdata orchestrator for data collection modules written in go";
     homepage = "https://github.com/netdata/go.d.plugin";
     license = licenses.gpl3;
-    maintainers = [ maintainers.lethalman ];
+    maintainers = [ ];
   };
 }