maintainers: add EarthGman (#392582)

maintainers/maintainer-list.nix

···
     githubId = 424946;
     name = "James Earl Douglas";
   };
+  EarthGman = {
+    email = "[e-mail]";
+    name = "EarthGman";
+    github = "EarthGman";
+    githubId = 117403037;
+  };
   EBADBEEF = {
     name = "EBADBEEF";
     email = "[e-mail]";