test: remove unneeded yarnrc creation in E2E setup

Author: clydin

tests/legacy-cli/e2e/setup/001-npm-sandbox.ts

@@ -11,7 +11,6 @@ export default async function () {
   const yarnModulesPrefix = join(tempRoot, 'yarn-global');
   const npmRegistry: string = getGlobalVariable('package-registry');
   const npmrc = join(tempRoot, '.npmrc');
-  const yarnrc = join(tempRoot, '.yarnrc');
 
   // Change the npm+yarn userconfig to the sandboxed npmrc to override the default ~
   process.env.NPM_CONFIG_USERCONFIG = npmrc;
@@ -37,7 +36,6 @@ export default async function () {
 
   // Configure the registry and prefix used within the test sandbox via rc files
   await writeFile(npmrc, `registry=${npmRegistry}\nprefix=${npmModulesPrefix}`);
-  await writeFile(yarnrc, `registry ${npmRegistry}\nprefix ${yarnModulesPrefix}`);
 
   await mkdir(npmModulesPrefix);
   await mkdir(yarnModulesPrefix);