submodule: bump openthread from `cc72e29` to `b2f8c4a` (#266)
submodule: bump openthread from `cc72e29` to `b2f8c4a` (#266)

Bumps [openthread](https://github.com/openthread/openthread) from `cc72e29` to `b2f8c4a`.
- [Commits](https://github.com/openthread/openthread/compare/cc72e29c88de7c0a1de51ccf823ac4d0a4336ace...b2f8c4adba26f44b2ca97fbae6d0e265775c0d69)

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

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

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
openthread/ot-b91,openthread/ot-b91