submodule: bump openthread from 151444f to 1024a1f

Bumps [openthread](https://github.com/openthread/openthread) from `151444f` to `1024a1f`.
- [Release notes](https://github.com/openthread/openthread/releases)
- [Commits](openthread/openthread@151444f...1024a1f)

---
updated-dependencies:
- dependency-name: openthread
  dependency-type: direct:production
...

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