chore(submodule): bump etc/data/nnet from f43cee9 to efa89e4

Bumps etc/data/nnet from `f43cee9` to `efa89e4`.

---
updated-dependencies:
- dependency-name: etc/data/nnet
  dependency-version: efa89e44d0c68e2107105cc39096b41d98bba590
  dependency-type: direct:production
...

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Author: dependabot[bot]