Chore(deps): Bump certifi in /services/valkey

Bumps [certifi](https://github.com/certifi/python-certifi) from 2026.7.22 to 2026.10.18.
- [Commits](certifi/python-certifi@2026.07.22...2026.10.18)

---
updated-dependencies:
- dependency-name: certifi
  dependency-version: 2026.10.18
  dependency-type: indirect
...

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Author: dependabot[bot]