submodule: bump third_party/openthread/repo from `d3e00fb` to `2b726ef` (#1561)
submodule: bump third_party/openthread/repo from `d3e00fb` to `2b726ef` (#1561)

Bumps [third_party/openthread/repo](https://github.com/openthread/openthread) from `d3e00fb` to `2b726ef`.
- [Commits](https://github.com/openthread/openthread/compare/d3e00fbd2846c09ff29444bd7cf895d3f4cff9b6...2b726ef29f5c6a58a30973d7b8defaa94a4dc4c4)

---
updated-dependencies:
- dependency-name: third_party/openthread/repo
  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-br-posix,openthread/borderrouter,openthread/borderrouter,openthread/borderrouter,openthread/ot-br-posix,openthread/borderrouter,openthread/ot-br-posix,openthread/borderrouter,openthread/ot-br-posix,openthread/ot-br-posix,openthread/borderrouter,openthread/ot-br-posix