Bump actions/setup-node from 5 to 6 (#5813)

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 5 to 6.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](https://github.com/actions/setup-node/compare/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] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Cenk Kücük <cenk@plausible.io>

.github/workflows/node.yml

@@ -21,7 +21,7 @@ jobs:
       uses: marocchino/tool-versions-action@v1
       id: versions
     - name: Set up Node
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v6
       with:
         node-version: ${{steps.versions.outputs.nodejs}}
     - run: npm install --prefix ./assets

.github/workflows/tracker-script-npm-release.yml

@@ -23,7 +23,7 @@ jobs:
         with:
           token: ${{ secrets.PLAUSIBLE_BOT_GITHUB_TOKEN }}
 
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: 23.2.0
           registry-url: 'https://registry.npmjs.org'

.github/workflows/tracker.yml

@@ -21,7 +21,7 @@ jobs:
         shardTotal: [4]
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: 23.2.0
           cache: 'npm'
@@ -61,7 +61,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: 23.2.0
           cache: 'npm'