SUMO-256677: updated test to run with node 20

Author: himanshu219

.github/workflows/syntax-validation-test.yaml

@@ -23,7 +23,7 @@ jobs:
       - name: Setup node
         uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
 
       - working-directory: ${{ matrix.dir }}
         run: |