Fix missing sed import (facebook#39964)

Summary:

Changelog: [Internal] - Fix missing sed import for Hermes flag fix in facebook@c03d520

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Reviewed By: cipolleschi

Differential Revision: D50016450

scripts/test-e2e-local.js

@@ -16,7 +16,7 @@
  * and to make it more accessible for other devs to play around with.
  */
 
-const {exec, pushd, popd, pwd, cd} = require('shelljs');
+const {exec, pushd, popd, pwd, cd, sed} = require('shelljs');
 const updateTemplatePackage = require('./update-template-package');
 const yargs = require('yargs');
 const path = require('path');