submodules: bump external/sapphire-paratime from a13bd49 to 398f116

Bumps [external/sapphire-paratime](https://github.com/oasisprotocol/sapphire-paratime) from `a13bd49` to `398f116`.
- [Release notes](https://github.com/oasisprotocol/sapphire-paratime/releases)
- [Commits](oasisprotocol/sapphire-paratime@a13bd49...398f116)

---
updated-dependencies:
- dependency-name: external/sapphire-paratime
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>