Bump engines.node to >=20

Signed-off-by: Sora Morimoto <[email protected]>

Author: smorimoto

package-lock.json

@@ -36,7 +36,7 @@
     "stylelint-config-standard-scss": "11.1.0"
   },
   "engines": {
-    "node": ">=18"
+    "node": ">=20"
   },
   "private": true
 }