chore(submodule): bump etc/data/nnet from 88cafa8 to ac13e7f

Bumps etc/data/nnet from `88cafa8` to `ac13e7f`.

---
updated-dependencies:
- dependency-name: etc/data/nnet
  dependency-version: ac13e7fcab0b5f0e68be421d7972a316b800b0ed
  dependency-type: direct:production
...

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Author: dependabot[bot]