ci: drop support for Node 18

ArangoJS 10 no longer supports Node 18, and it will be EOL soon.

Author: Yogu

.github/workflows/ci.yml

@@ -5,8 +5,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        arango-image: ['arangodb:3.8', 'arangodb:3.11', 'arangodb:3.12']
-        node-version: [18.x, 20.x, 22.x]
+        arango-image: ["arangodb:3.8", "arangodb:3.11", "arangodb:3.12"]
+        node-version: [20.x, 22.x]
     steps:
       - uses: actions/checkout@v2
       - name: Use Node.js ${{ matrix.node-version }}
@@ -28,7 +28,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v1
         with:
-          node-version: 18
+          node-version: 22
           registry-url: https://registry.npmjs.org/
       - run: npm ci
       - run: npm publish --tag next