test: Add Node 20 to CI matrix (#978)

.github/workflows/ci.yml

@@ -11,19 +11,21 @@ on:
 jobs:
   tests:
     runs-on: ubuntu-20.04
+    strategy:
+      matrix:
+        node: [18, 20]
+    continue-on-error: ${{ matrix.node == 20 }}
 
     steps:
     - name: Checkout
       uses: actions/checkout@v3
-    - name: Setup Nodejs Env
-      run: echo "NODE_VER=`cat .nvmrc`" >> $GITHUB_ENV
     - name: Setup Nodejs
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v4
       with:
-        node-version: ${{ env.NODE_VER }}
+        node-version: ${{ matrix.node }}
 
     - name: Install NPM
-      run: npm install -g npm@${{ matrix.npm }}
+      run: npm install
 
     - name: Install Dependencies
       run: npm ci