Bump pnpm/action-setup from 2 to 4

Bumps [pnpm/action-setup](https://github.com/pnpm/action-setup) from 2 to 4.
- [Release notes](https://github.com/pnpm/action-setup/releases)
- [Commits](pnpm/action-setup@v2...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/docs.yml

@@ -22,7 +22,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: pnpm/action-setup@v2
+      - uses: pnpm/action-setup@v4
         with:
           version: 8
       - name: Setup Node