Update actions/setup-node action to v6

Author: renovate[bot]

.github/workflows/pr-checks.yaml

@@ -25,7 +25,7 @@ jobs:
           fetch-depth: 0 # Required for MegaLinter
 
       - name: Setup node
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version-file: .nvmrc
 
@@ -56,7 +56,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Setup node
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version-file: .nvmrc