maintainers: add samuelgrf

maintainers/maintainer-list.nix

@@ -7218,6 +7218,16 @@
     githubId = 132835;
     name = "Samuel Dionne-Riel";
   };
+  samuelgrf = {
+    email = "git@samuelgrf.com";
+    github = "samuelgrf";
+    githubId = 67663538;
+    name = "Samuel Gräfenstein";
+    keys = [{
+      longkeyid = "rsa4096/0xEF76A063F15C63C8";
+      fingerprint = "FF24 5832 8FAF 4660 18C6  186E EF76 A063 F15C 63C8";
+    }];
+  };
   samuelrivas = {
     email = "samuelrivas@gmail.com";
     github = "samuelrivas";