nixos/pufferpanel: buildFHSUserEnv -> buildFHSEnv

The pufferpanel module (#225274) was merged shortly after the tree-wide
rename f63a12f296 (#225748), so the use of
deperecated buildFHSUserEnv in the docs slipped through review 😅

nixos/modules/services/misc/pufferpanel.nix

@@ -19,7 +19,7 @@ in
           services.pufferpanel = {
             enable = true;
             extraPackages = with pkgs; [ bash curl gawk gnutar gzip ];
-            package = pkgs.buildFHSUserEnv {
+            package = pkgs.buildFHSEnv {
               name = "pufferpanel-fhs";
               runScript = lib.getExe pkgs.pufferpanel;
               targetPkgs = pkgs': with pkgs'; [ icu openssl zlib ];
@@ -162,7 +162,7 @@ in
         PrivateUsers = true;
         PrivateDevices = true;
         RestrictRealtime = true;
-        RestrictNamespaces = [ "user" "mnt" ]; # allow buildFHSUserEnv
+        RestrictNamespaces = [ "user" "mnt" ]; # allow buildFHSEnv
         RestrictAddressFamilies = [ "AF_INET" "AF_INET6" "AF_UNIX" ];
         LockPersonality = true;
         DeviceAllow = [ "" ];