web: add default export to CJS bundle

(cherry picked from commit 081c90b769)

lib/binding_web/script/build.js

@@ -44,6 +44,9 @@ async function build() {
     keepNames: true,
     external: ['fs/*', 'fs/promises'],
     resolveExtensions: ['.ts', '.js', format === 'esm' ? '.mjs' : '.cjs'],
+    ...(format === 'cjs' ? {
+      footer: { js: 'module.exports.default = module.exports;' },
+    } : {}),
   });
 
   // Copy the Wasm files to the appropriate spot, as esbuild doesn't "bundle" Wasm files