submodule: bump openthread from `2796615` to `8467a3d` (#29)
submodule: bump openthread from `2796615` to `8467a3d` (#29)

Bumps [openthread](https://github.com/openthread/openthread) from `2796615` to `8467a3d`.
- [Commits](https://github.com/openthread/openthread/compare/2796615cf7e64bc0fc633b6f8c6430dade1b466d...8467a3d5223c274b65a71080f6aad94dc182a9bb)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
openthread/ot-nrf528xx,openthread/ot-nrf528xx