community-builder: set shell to fish for linj

modules/darwin/community-builder/users.nix

@@ -291,6 +291,7 @@ let
       name = "linj";
       trusted = true;
       uid = 547;
+      shell = pkgs.fish;
       keys = ./keys/linj;
     }
     {

modules/nixos/community-builder/users.nix

@@ -94,6 +94,7 @@ let
     linj = {
       # lib.maintainers.linj, https://github.com/jian-lin
       trusted = true;
+      shell = pkgs.fish;
       keys = ./keys/linj;
     };