submodule: bump third_party/openthread/repo from `349041b` to `8210a02` (#1389)
submodule: bump third_party/openthread/repo from `349041b` to `8210a02` (#1389)

Bumps [third_party/openthread/repo](https://github.com/openthread/openthread) from `349041b` to `8210a02`.
- [Commits](https://github.com/openthread/openthread/compare/349041bc61e899acdccefea455c3401c05e1318b...8210a02400c145eb862b65e32040ed0415ba36c2)

---
updated-dependencies:
- dependency-name: third_party/openthread/repo
  dependency-type: direct:production
...

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

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