```
The usage of MilliSleep() in SeedPeriodic (previously SeedSleep) was
removed in #17270, meaning it, and its users can now be marked noexcept.
This also corrects the docs in random.h for some of the changes in #17270.
```
Backport of core [[https://github.com/bitcoin/bitcoin/pull/17507 | PR17507]].
Depends on D6209.