Bump third_party/nanopb/repo from 41319af to 671672b (#32400)

Bumps [third_party/nanopb/repo](https://github.com/nanopb/nanopb) from `41319af` to `671672b`.
- [Commits](nanopb/nanopb@41319af...671672b)

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

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