Old info in the CI documentation

[daniel-6over6]

It's written here:
https://docs.fastlane.tools/best-practices/continuous-integration/

"An Apple ID session is only valid for up to a month, meaning you'll have to generate a new session every month. Usually you'd only know about it when your build starts failing"

I ran "fastlane spaceauth -u user@email.com" and configured CircleCI FASTLANE_SESSION environment variable with with output of fastlane spaceauth.

The reality is that FASTLANE_SESSION only lasts for about 6 - 24 hours.
After googling the issue, I found this happens to a lot of people and that for some time now the sessions don't last 24. Documentation should be updated accordingly.