💥 Drop Node.js v20 from CI (#1488)

Author: KATO-Hiro

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [20.x, 22.x]
+        node-version: [22.x]
 
     steps:
       - name: Check out Git repository