Remove the locked version of sysrandom

[CDeighton]

Currently this gem uses https://github.com/cryptosphere/sysrandom, which is a version of securerandom that has been dead since 2018. It seems to have been used as a workaround to this long running issue (from 2014) which looks to now be long resolved - https://bugs.ruby-lang.org/issues/9569

This is an issue for 2 reasons:

• Relying on unsupported gems might result in security issues (unlikely in something like this, but worth keeping in mind)
• It appears to overload SecureRandom, which breaks a bunch of other gems that rely on randomisation (this is my selfish case 🙂)

If applied this commit will remove this locked version and start relying on the ruby stdlib version of securerandom instead which is supported and relied on by other gems

DISCLAIMER: Unfortunately I'm not a security expert, so I could well be missing a detail on this. But as far as I can tell the issue referenced is long resolved.

I've managed to run this fork to be able to log in to ASC and collect review and app data successfully

[Loriowar]

+1 the old gem usage leads to unexpected problem with random numbers in multiple libs/gems. Because random_number method in the old gem allows to pass only number, not range. In the modern implementation of random_number from Random::Formatter there are three variants of the input args (no arg, int or range). However, the outdated sysrandom has only two (no arg or int).

[kstevens715]

👍 The dependency on sysrandom is causing a lot of problems in my app in areas completely unrelated to fastlane. A similar issue was opened in the main fastlane repo here: fastlane/fastlane#26682, and another sysrandom related issue here: fastlane/fastlane#26655.

[kstevens715]

I forked this gem and made the changes in this PR in the fork. The changes have now been in my production app for ~24 hours and it has resolved the problems I was having.