Bump omz-custom/plugins/zsh-completions from 7dd26c5 to 684021f

Bumps [omz-custom/plugins/zsh-completions](https://github.com/zsh-users/zsh-completions) from `7dd26c5` to `684021f`.
- [Release notes](https://github.com/zsh-users/zsh-completions/releases)
- [Commits](zsh-users/zsh-completions@7dd26c5...684021f)

---
updated-dependencies:
- dependency-name: omz-custom/plugins/zsh-completions
  dependency-version: 684021f2a1eb3ba1735d86268c07bce8b0ea0588
  dependency-type: direct:production
...

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Author: dependabot[bot]