chore: update actions/setup-node action to v6

Author: renovate[bot]

.github/workflows/CI.yml

@@ -21,7 +21,7 @@ jobs:
         mkdir -p ${{ env.MIWG_PATH }}
         git clone https://github.com/bpmn-io/bpmn-miwg-test-suite.git ${{ env.MIWG_PATH }}
     - name: Use Node.js
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v6
       with:
         node-version: ${{ matrix.node-version }}
         cache: 'npm'

.github/workflows/MIWG.yml

@@ -27,7 +27,7 @@ jobs:
         mkdir -p ${{ env.MIWG_PATH }}
         git clone https://github.com/bpmn-io/bpmn-miwg-test-suite.git ${{ env.MIWG_PATH }}
     - name: Use Node.js
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v6
       with:
         node-version: ${{ matrix.node-version }}
     - name: Install dependencies