Remove duplicate code

src/index.js

@@ -12,14 +12,6 @@ if (
   worker.start();
 }
 
-if (
-  process.env.NODE_ENV === "development" &&
-  process.env.REACT_APP_MOCK_CCCE_API === "YES"
-) {
-  const { worker } = require("./mocks/browser");
-  worker.start();
-}
-
 // Set license key
 LicenseInfo.setLicenseKey(process.env.REACT_APP_MUI_PRO_LICENSE_KEY);