Bump third_party/pigweed/repo from 1f12d06 to 1247e8d

Bumps [third_party/pigweed/repo](https://github.com/google/pigweed) from `1f12d06` to `1247e8d`.
- [Commits](google/pigweed@1f12d06...1247e8d)

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

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