fix another GHA log panic

Author: jyn514

src/bootstrap/doc.rs

@@ -220,6 +220,9 @@ impl Step for TheBook {
         // build the version info page and CSS
         let shared_assets = builder.ensure(SharedAssets { target });
 
+        // build the command first so we don't nest GHA groups
+        builder.rustdoc_cmd(compiler);
+
         // build the redirect pages
         let _guard = builder.msg_doc(compiler, "book redirect pages", target);
         for file in t!(fs::read_dir(builder.src.join(&relative_path).join("redirects"))) {