submodule: bump openthread from `a274dde` to `63e4b7c` (#10)
submodule: bump openthread from `a274dde` to `63e4b7c` (#10)

Bumps [openthread](https://github.com/openthread/openthread) from `a274dde` to `63e4b7c`.
- [Commits](https://github.com/openthread/openthread/compare/a274ddea7161da09251a43c82fa62070a745115b...63e4b7c9ea7d87a29577a97dfdbeb225dbc2ec3c)

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

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