nix-plugin-pijul: drop (#405407)

Author: isabelroses

pkgs/by-name/ni/nix-plugin-pijul/package.nix

@@ -1328,6 +1328,7 @@ mapAliases {
   newlib-nanoCross = newlib-nano; # Added 2024-09-06
   nix-direnv-flakes = nix-direnv;
   nix-ld-rs = nix-ld; # Added 2024-08-17
+  nix-plugin-pijul = throw "nix-plugin-pijul has been removed due to being discontinued"; # added 2025-05-18
   nix-repl = throw (
     # Added 2018-08-26
     "nix-repl has been removed because it's not maintained anymore, "