Bump actions/setup-node from 5 to 6 (#394)

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 5 to 6.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@v5...v6)

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

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: 'lts/*'
           check-latest: true
@@ -47,7 +47,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: ${{ matrix.node-version }}
           check-latest: true
@@ -92,7 +92,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: dart-lang/setup-dart@v1
         with: {sdk: stable}
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with: {node-version: "${{ matrix.node_version }}"}
 
       - name: Check out Dart Sass
@@ -131,7 +131,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: 'lts/*'
           check-latest: true