fix vitepress config

Author: ota-meshi

docs/.vitepress/config.mts

@@ -162,16 +162,12 @@ export default async () => {
 
           tslib: path.join(dirname, '../../node_modules/tslib/tslib.es6.js'),
           globby: path.join(dirname, './build-system/shim/empty.mjs'),
-          'fast-glob': path.join(dirname, './build-system/shim/empty.mjs')
+          'fast-glob': path.join(dirname, './build-system/shim/empty.mjs'),
+          module: path.join(dirname, './build-system/shim/empty.mjs')
         }
       },
       define: {
         'require.cache': '{}'
-      },
-      build: {
-        rollupOptions: {
-          external: ['module']
-        }
       }
     },