tools: fix doc generation when version info is not available

Fixes: #38391

PR-URL: #38398
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>

tools/doc/generate.js

@@ -43,7 +43,7 @@ let filename = null;
 let nodeVersion = null;
 let outputDir = null;
 let apilinks = {};
-let versions = {};
+let versions = [];
 
 async function main() {
   for (const arg of args) {