Bump third_party/pigweed/repo from ce0e3e2 to b8d1cd0

Bumps [third_party/pigweed/repo](https://github.com/google/pigweed) from `ce0e3e2` to `b8d1cd0`.
- [Commits](google/pigweed@ce0e3e2...b8d1cd0)

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

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