Bump actions/setup-node from 2.5.1 to 3 (#537)

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 2.5.1 to 3.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](https://github.com/actions/setup-node/compare/v2.5.1...v3)

---
updated-dependencies:
- dependency-name: actions/setup-node
  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/autoprefixer.yml

@@ -11,7 +11,7 @@ jobs:
         uses: actions/checkout@v2.4.0
 
       - name: Setup Node
-        uses: actions/setup-node@v2.5.1
+        uses: actions/setup-node@v3
         with:
           node-version: "15.x"