submodule: bump openthread from `645fbcd` to `c2dd7eb` (#213)
submodule: bump openthread from `645fbcd` to `c2dd7eb` (#213)

Bumps [openthread](https://github.com/openthread/openthread) from `645fbcd` to `c2dd7eb`.
- [Commits](https://github.com/openthread/openthread/compare/645fbcd400d2e6c2de641bccb0335e3eaaed1f36...c2dd7eb66d5d806adf6fb2dcb35e2070e97f2e78)

---
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