deps(ci): bump actions/setup-node from 5 to 6

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>

.github/workflows/release.yml

@@ -84,7 +84,7 @@ jobs:
         if: needs.version.outputs.should_release #only redo if the version changed
         run: sed -i -e "s/version=.*/version=${{ needs.version.outputs.version_next }}/" gradle.properties
 
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version-file: '.nvmrc'
           cache: 'npm'

.github/workflows/tests.yml

@@ -79,7 +79,7 @@ jobs:
     name: Test webui builds
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version-file: '.nvmrc'
           cache: 'npm'