ci: update node lts version

Author: sxzz

.github/workflows/ci.yml

@@ -39,9 +39,9 @@ jobs:
         include:
           # Active LTS + other OS
           - os: macos-latest
-            node_version: 18
+            node_version: 20
           - os: windows-latest
-            node_version: 18
+            node_version: 20
       fail-fast: false
 
     name: "Build&Test: node-${{ matrix.node_version }}, ${{ matrix.os }}"