chore(submodule): bump etc/data/nnet from 8767b2e to 88cafa8

Bumps etc/data/nnet from `8767b2e` to `88cafa8`.

---
updated-dependencies:
- dependency-name: etc/data/nnet
  dependency-version: 88cafa8a1cf51a022680398a8502827cba1f5858
  dependency-type: direct:production
...

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

Author: dependabot[bot]