Update dependency @actions/github to v4

Author: renovate-bot

package-lock.json

@@ -26,7 +26,7 @@
   "license": "MIT",
   "dependencies": {
     "@actions/core": "1.2.4",
-    "@actions/github": "3.0.0",
+    "@actions/github": "4.0.0",
     "@octokit/webhooks": "7.8.1",
     "git-blame-json": "1.0.1",
     "php-codesniffer": "1.0.2",