Keep using module.useNode() instead of bundling server node_modules.

This partially reverts commit 4dfc74197a.

Some server packages, especially those that rely on __dirname or
__filename (e.g. puppeteer), simply cannot be included in the server
bundle, and must be evaluated natively by Node.

As long as we have a Module.prototype._compile hook to process natively
evaluated modules with Reify, module.useNode() can still benefit from ESM
import/export syntax.

tools/isobuild/import-scanner.js

@@ -1222,17 +1222,6 @@ export default class ImportScanner {
       return false;
     }
 
-    if (
-      absModuleId.endsWith(".js") ||
-      absModuleId.endsWith(".mjs")
-    ) {
-      return false;
-    }
-
-    if (absModuleId.endsWith(".node")) {
-      return true;
-    }
-
     const parts = absModuleId.split("/");
     let start = 0;