Bump third_party/pigweed/repo from 9e4bfb9 to 3cfe5d0

Bumps [third_party/pigweed/repo](https://github.com/google/pigweed) from `9e4bfb9` to `3cfe5d0`.
- [Commits](google/pigweed@9e4bfb9...3cfe5d0)

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

Signed-off-by: dependabot[bot] <[email protected]>