chore: Upgrade GitHub Action runtime from Node 20 to Node 24 (#63)

Update action.yml to use node24 runtime and bump engines.node to >=24
in package.json. Rebuild dist/index.js.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: goruha

action.yml

@@ -13,7 +13,7 @@ inputs:
     required: true
     description: "YAML config"
 runs:
-  using: node20
+  using: node24
   main: 'dist/index.js'
 
 #  env:

package.json

@@ -7,7 +7,7 @@
     ".": "./dist/index.js"
   },
   "engines": {
-    "node": ">=20"
+    "node": ">=24"
   },
   "scripts": {
     "format:write": "npx prettier --write .",