maintainers: update samuelgrf's email and keys

maintainers/maintainer-list.nix

@@ -10622,14 +10622,20 @@
     name = "Samuel Dionne-Riel";
   };
   samuelgrf = {
-    email = "git@samuelgrf.com";
+    email = "s@muel.gr";
     github = "samuelgrf";
     githubId = 67663538;
     name = "Samuel Gräfenstein";
-    keys = [{
-      longkeyid = "rsa4096/0xEF76A063F15C63C8";
-      fingerprint = "FF24 5832 8FAF 4660 18C6  186E EF76 A063 F15C 63C8";
-    }];
+    keys = [
+      {
+        longkeyid = "rsa4096/0xDE75F92E318123F0";
+        fingerprint = "6F2E 2A90 423C 8111 BFF2  895E DE75 F92E 3181 23F0";
+      }
+      {
+        longkeyid = "rsa4096/0xEF76A063F15C63C8";
+        fingerprint = "FF24 5832 8FAF 4660 18C6  186E EF76 A063 F15C 63C8";
+      }
+    ];
   };
   samuelrivas = {
     email = "samuelrivas@gmail.com";