Raise minimum Node.js version to 20, test on 24 (#34713)

- Node.js 18 is now EOL, so raise minimum version to current LTS v20
- Test on 24
- Change devcontainers to use LTS version (currently 22),
[ref](https://github.com/devcontainers/features/tree/main/src/node)

package.json

@@ -1,7 +1,7 @@
 {
   "type": "module",
   "engines": {
-    "node": ">= 18.0.0"
+    "node": ">= 20.0.0"
   },
   "dependencies": {
     "@citation-js/core": "0.7.18",