remove extraneous build target

Author: Feiyang1

packages-exp/functions-exp/rollup.config.js

@@ -40,10 +40,7 @@ const es5Builds = [
    */
   {
     input: 'src/index.ts',
-    output: [
-      { file: pkg.browser, format: 'cjs', sourcemap: true },
-      { file: pkg.module, format: 'es', sourcemap: true }
-    ],
+    output: [{ file: pkg.module, format: 'es', sourcemap: true }],
     plugins: es5BuildPlugins,
     external: id => deps.some(dep => id === dep || id.startsWith(`${dep}/`))
   },