fix: package.json & package-lock.json to reduce vulnerabilities (#129)

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-ACTIONSCORE-2980270

package.json

@@ -26,7 +26,7 @@
   "author": "Naoki Oketani <okepy.naoki@gmail.com>",
   "license": "MIT",
   "dependencies": {
-    "@actions/core": "^1.9.0",
+    "@actions/core": "^1.9.1",
     "@actions/github": "^5.0.3",
     "@octokit/rest": "^18.12.0",
     "axios": "^0.27.2",