fix: avoid smtp source IFD

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

test/package/default.nix

@@ -1,4 +1,9 @@
 { system, inputs, self, pkgs }:
+let
+  smtpPackages = map
+    (version: self.packages.${system}."pg-${version}-ext-smtp-client")
+    [ "15" "16" "17" ];
+in
   (import ./migrator      { inherit system inputs self pkgs; }) //
   (import ./hemar         { inherit system inputs self pkgs; }) //
   (import (./. + "/sentinèlla") { inherit system inputs self pkgs; }) //
@@ -7,4 +12,12 @@
   (import ./with-attic-cache { inherit system inputs self pkgs; }) //
   (import ./element-web   { inherit system inputs self pkgs; }) //
   (import ./linux-devshell { inherit system inputs self pkgs; }) //
-  (import ./windows-devshell { inherit system inputs self pkgs; })
+  (import ./windows-devshell { inherit system inputs self pkgs; }) //
+  {
+    pg-smtp-client-metadata =
+      assert builtins.all (package: package.pname == "pg_smtp_client") smtpPackages;
+      assert builtins.all (package: package.version == "0.2.0") smtpPackages;
+      pkgs.runCommand "pg-smtp-client-metadata" {} ''
+        touch "$out"
+      '';
+  }