bpb: remove myself from maintainers

Git 2.34 allows using OpenSSH keys for signing commits:
https://github.com/community/community/discussions/7744

pkgs/tools/security/bpb/default.nix

···
     description = "Tool to automatically sign git commits, replacing gpg for that purpose";
     homepage = "https://github.com/withoutboats/bpb";
     license = licenses.mit;
-    maintainers = with maintainers; [ jtojnar ];
+    maintainers = with maintainers; [ ];
   };
 }