chore: update node version used in CI

Author: thomasthiebaud

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [18]
+        node-version: [20]
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2