fix: upgrade tmp to 0.2.6 to resolve path traversal vulnerability (#560)

Addresses GHSA-ph9p-34f9-6g65.

TAG=agy
CONV=6ccca40c-ae16-4bff-a10b-e7f61521a5f1

Author: suztomo

action/package-lock.json

@@ -44,7 +44,7 @@
     "typescript": "^5.7.3"
   },
   "overrides": {
-    "tmp": "0.2.5",
+    "tmp": "0.2.6",
     "serialize-javascript": "^7.0.5",
     "handlebars": "^4.7.9"
   }

action/package.json

@@ -67,7 +67,7 @@
     "webpack-cli": "^5.0.0"
   },
   "overrides": {
-    "tmp": "0.2.5",
+    "tmp": "0.2.6",
     "diff": "^8.0.3",
     "serialize-javascript": "^7.0.5"
   }