Update actions/setup-node action to v6

Author: renovate[bot]

.github/workflows/test-testdata.yml

@@ -20,7 +20,7 @@ jobs:
 
     - uses: actions/checkout@v5
 
-    - uses: actions/setup-node@v5
+    - uses: actions/setup-node@v6
       with:
         cache: 'npm'
         cache-dependency-path: testdata/package-lock.json