nixos/github-runners: add nodeRuntimes option

nixos/modules/services/continuous-integration/github-runner/options.nix

@@ -208,4 +208,12 @@ with lib;
     '';
     default = null;
   };
+
+  nodeRuntimes = mkOption {
+    type = with types; nonEmptyListOf (enum [ "node16" "node20" ]);
+    default = [ "node20" ];
+    description = mdDoc ''
+      List of Node.js runtimes the runner should support.
+    '';
+  };
 }

nixos/modules/services/continuous-integration/github-runner/service.nix

@@ -22,6 +22,7 @@ with lib;
 
 let
   workDir = if cfg.workDir == null then runtimeDir else cfg.workDir;
+  package = cfg.package.override { inherit (cfg) nodeRuntimes; };
 in
 {
   description = "GitHub Actions runner";
@@ -47,7 +48,7 @@ in
 
   serviceConfig = mkMerge [
     {
-      ExecStart = "${cfg.package}/bin/Runner.Listener run --startuptype service";
+      ExecStart = "${package}/bin/Runner.Listener run --startuptype service";
 
       # Does the following, sequentially:
       # - If the module configuration or the token has changed, purge the state directory,
@@ -149,7 +150,7 @@ in
               else
                 args+=(--token "$token")
               fi
-              ${cfg.package}/bin/Runner.Listener configure "''${args[@]}"
+              ${package}/bin/Runner.Listener configure "''${args[@]}"
               # Move the automatically created _diag dir to the logs dir
               mkdir -p  "$STATE_DIRECTORY/_diag"
               cp    -r  "$STATE_DIRECTORY/_diag/." "$LOGS_DIRECTORY/"