[flake] add en/fr build targets

flake.nix

@@ -63,6 +63,21 @@
             zh = "zh_core_news_trf";
           };
 
+          mkSpacyDerivation = lang:
+            pkgs.stdenv.mkDerivation {
+              name = "spacy-${lang}";
+              # no src, see
+              # https://github.com/NixOS/nixpkgs/issues/23099
+              dontUnpack = true;
+              buildInputs = [
+                (pythonWithModel (langMap."${lang}"))
+                (server (langMap."${lang}"))
+              ];
+              installPhase = ''
+                touch $out
+              '';
+            };
+
           mkDevShell = lang: pkgs.mkShell {
             buildInputs = [
               (pythonWithModel (langMap."${lang}"))
@@ -76,6 +91,9 @@
         {
           devShells.en = mkDevShell "en";
           devShells.fr = mkDevShell "fr";
+
+          packages.en = mkSpacyDerivation "en";
+          packages.fr = mkSpacyDerivation "fr" ;
         }
     );
 }