build(deps): bump third_party/cctz from d139743 to 70c3bd1

Bumps [third_party/cctz](https://github.com/google/cctz) from `d139743` to `70c3bd1`.
- [Release notes](https://github.com/google/cctz/releases)
- [Commits](google/cctz@d139743...70c3bd1)

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

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