Bump third_party/pigweed/repo from b7f7852 to 96665e8 (#24450)

Bumps [third_party/pigweed/repo](https://github.com/google/pigweed) from `b7f7852` to `96665e8`.
- [Release notes](https://github.com/google/pigweed/releases)
- [Commits](google/pigweed@b7f7852...96665e8)

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

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

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