meta-*: bump poky from 7d50718 to 8643f91 in the layers group

Bumps the layers group with 1 update: poky.


Updates `poky` from `7d50718` to `8643f91`

---
updated-dependencies:
- dependency-name: poky
  dependency-version: 8643f911602949518c5c5474726b49f943e36b83
  dependency-type: direct:production
  dependency-group: layers
...

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Author: dependabot[bot]