Bump third_party/pigweed/repo from 90d97fa to 5eccd87 (#30440)

Bumps [third_party/pigweed/repo](https://github.com/google/pigweed) from `90d97fa` to `5eccd87`.
- [Commits](google/pigweed@90d97fa...5eccd87)

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

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