submodule: bump openthread from ec93c24 to 94822ea (#509)

Bumps [openthread](https://github.com/openthread/openthread) from `ec93c24` to `94822ea`.
- [Commits](openthread/openthread@ec93c24...94822ea)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>