chore(deps): update actions/setup-node action to v6 (#20)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/test-testdata.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           cache: 'npm'
           cache-dependency-path: testdata/compatibility-kit/package-lock.json
@@ -40,7 +40,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           cache: 'npm'
           cache-dependency-path: testdata/json-schema/package-lock.json