chore(deps): bump pnpm/action-setup from 4 to 6 (#9)

Bumps [pnpm/action-setup](https://github.com/pnpm/action-setup) from 4 to 6.
- [Release notes](https://github.com/pnpm/action-setup/releases)
- [Commits](https://github.com/pnpm/action-setup/compare/v4...v6)

---
updated-dependencies:
- dependency-name: pnpm/action-setup
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

cloudflare-worker/.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
-      - uses: pnpm/action-setup@v4
+      - uses: pnpm/action-setup@v6
       - uses: actions/setup-node@v6
         with:
           node-version: '24'