Magento Enterprise Cloud Edition bug: «The file "/composer.json" doesn't exist»

Luckily, I was able to reproduce a similar issue and investigate it:

With a high probability it is the same issue as yours, and I have created a workaround for it the 2.9.9 version of the mage2pro/core package.

Just upgrade your Stripe extension and try to redeploy your website to production again.