niv motoko-base: update 1f52c6b8 -> 1b116fe9 (#4195)

## Changelog for motoko-base:
Branch: next-moc
Commits: [dfinity/motoko-base@1f52c6b8...1b116fe9](dfinity/motoko-base@1f52c6b...1b116fe)

* [`1b116fe9`](dfinity/motoko-base@1b116fe) feat: `Region.mo` library offering isolated regions of IC stable memory ([dfinity/motoko-base⁠#580](https://togithub.com/dfinity/motoko-base/issues/580))