Bump third_party/pigweed/repo from b88cd71 to 5c4ea8e (#26312)

Bumps [third_party/pigweed/repo](https://github.com/google/pigweed) from `b88cd71` to `5c4ea8e`.
- [Release notes](https://github.com/google/pigweed/releases)
- [Commits](google/pigweed@b88cd71...5c4ea8e)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>