labeler action is misconfigured

This is an issue instead of a PR because I don't know what the intended "correct" is, so treat it as a choose your own adventure PR.

---

The labeler action is currently not configured to match proposals in departments/cargo (using the old cargo-salvage name instead).

Additionally, there's an inconsistency with the main repo: this repo is currently using actions/labeler v4. Main repo is using v5.

Latest is v6 (which doesn't seem to introduce significant changes?). Regardless, available versions are in the action repo's tags, with changelogs in the releases.

Past configuration attempts, but correct

Based on @VasilisThePikachu's attempts from https://github.com/space-wizards/docs/commits/master/.github/labeler.yml)

For labeler v4

"Design":
- 'src/en/general-proposals/**'
- 'src/en/space-station-14/*/proposals/**'
- 'src/en/space-station-14/departments/*/proposals/**'

or more generic

"Design":
- 'src/en/general-proposals/**'
- 'src/en/**/proposals/**'

For labeler v5

"Design":
- changed-files:
  - any-glob-to-any-file:
    - 'src/en/general-proposals/**'
    - 'src/en/space-station-14/*/proposals/**'
    - 'src/en/space-station-14/departments/*/proposals/**'

or more generic

"Design":
- changed-files:
  - any-glob-to-any-file:
    - 'src/en/general-proposals/**'
    - 'src/en/**/proposals/**'

More broad

Arguably, all changes to src/en/space-station-14/** are design changes. Going back, some PRs which should be tagged Design... weren't. As such:

For labeler v4

"Design":
- 'src/en/general-proposals/**'
- 'src/en/space-station-14/**'

For labeler v5

"Design":
- changed-files:
  - any-glob-to-any-file:
    - 'src/en/general-proposals/**'
    - 'src/en/space-station-14/**'

Give up

Arguably-er, blindly tagging all commits which touch a design document with the Design tag is silly. Fixing a typo doesn't mean someone is codifying the game's design.

This begs the question: is the tag supposed to indicate which part of the docs are affected, or what the PR is intended to introduce? If it's the latter, maybe the Design tag just shouldn't be automatically added.

^{This PR brought to you by: sleepy rambling}

Start with .github/workflows/labeler-pr.yml and .github/labeler.yml, then compare the documented actions/labeler versions and prior configuration attempts. Decide whether Design should describe affected documentation paths or introduced design content; done means the chosen policy is configured, the version is intentional, and representative pull requests receive the expected label.