assimp: remove ehmry from maintainers

pkgs/by-name/as/assimp/package.nix

···
     mainProgram = "assimp";
     homepage = "https://www.assimp.org/";
     license = lib.licenses.bsd3;
-    maintainers = with lib.maintainers; [ ehmry ];
+    maintainers = [ ];
     platforms = lib.platforms.linux ++ lib.platforms.darwin;
   };
 })