feat(tests): add Jest configuration and comprehensive tests for utility functions in index.js to ensure functionality and reliability

chore(package): update @actions/github dependency to version 6.0.1 and add Jest as a dev dependency with a test script

package.json

@@ -23,7 +23,13 @@
   "license": "MIT",
   "dependencies": {
     "@actions/core": "^1.10.1",
-    "@actions/github": "^5.1.1",
+    "@actions/github": "^6.0.1",
     "node-fetch": "^3.3.2"
+  },
+  "devDependencies": {
+    "jest": "^30.0.0"
+  },
+  "scripts": {
+    "test": "node --experimental-vm-modules node_modules/.bin/jest"
   }
 }