submodule: bump openthread from `a34d117` to `812c36f` (#363)
submodule: bump openthread from `a34d117` to `812c36f` (#363)

Bumps [openthread](https://github.com/openthread/openthread) from `a34d117` to `812c36f`.
- [Commits](https://github.com/openthread/openthread/compare/a34d1176b969f1a662fa01ab7b9fde57e3602e8a...812c36f6581967b3d9af8361f00716c75f47473c)

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

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

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
openthread/ot-samr21,openthread/ot-samr21