update-scripts/version-info: get channel status for supported versions

Fetch channel info from NixOS/infra, the canonical source of truth.

(cherry picked from commit 9328f4437d)

update-scripts/version-info/default.nix

@@ -2,19 +2,41 @@
   lib,
   callPackage,
   writeShellApplication,
+  stdenv,
 }:
 let
   mainInfo = callPackage ./main.nix { };
+  channelsURL = "https://raw.githubusercontent.com/NixOS/infra/refs/heads/main/channels.nix";
 in
 writeShellApplication {
   name = "version-info";
+
+  runtimeEnv = {
+    NIX_CONFIG = ''
+      experimental-features = nix-command flakes pipe-operators
+    '';
+  };
+
   text = ''
+    # Download channel info from NixOS/infra
+    curl ${channelsURL} | nix eval --file - --json > channels.json
+
+    # Use channels.nix to build channels.toml
+    nix build --impure \
+      --inputs-from ${toString ../..} \
+      --file ${./supported-versions.nix} \
+      --argstr system ${stdenv.hostPlatform.system} \
+      --arg-from-file channelsJSON channels.json \
+      --out-link channels.toml
+
     (
       echo "# DO NOT MODIFY!"
       echo "# This file was generated by ${
         lib.strings.removePrefix (toString ../.. + "/") (toString ./default.nix)
       }"
       cat ${mainInfo}
+      echo
+      cat channels.toml
     ) > version-info.toml
   '';
 }