build(deps): bump pnpm/action-setup from 3 to 5 (#7410)

Bumps [pnpm/action-setup](https://github.com/pnpm/action-setup) from 3 to 5.
- [Release notes](https://github.com/pnpm/action-setup/releases)
- [Commits](pnpm/action-setup@v3...v5)

---
updated-dependencies:
- dependency-name: pnpm/action-setup
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/update-plugins.yml

@@ -12,7 +12,7 @@ jobs:
       - name: Check out etherpad-lite
         uses: actions/checkout@v4
 
-      - uses: pnpm/action-setup@v3
+      - uses: pnpm/action-setup@v5
         name: Install pnpm
         with:
           version: 10