Bump pnpm/action-setup from 2 to 4 in /.github/workflows (#4798)

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

---
updated-dependencies:
- dependency-name: pnpm/action-setup
  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>

.github/workflows/tests.yml

@@ -77,7 +77,7 @@ jobs:
           pio upgrade
 
       - name: Setup pnpm
-        uses: pnpm/action-setup@v2
+        uses: pnpm/action-setup@v4
         with:
           version: latest