Bump google-auth-library from 9.6.0 to 9.6.1 in /scripts/gcb2slack (#3333)

Bumps [google-auth-library](https://github.com/googleapis/google-auth-library-nodejs) from 9.6.0 to 9.6.1.
- [Release notes](https://github.com/googleapis/google-auth-library-nodejs/releases)
- [Changelog](https://github.com/googleapis/google-auth-library-nodejs/blob/main/CHANGELOG.md)
- [Commits](googleapis/google-auth-library-nodejs@v9.6.0...v9.6.1)

---
updated-dependencies:
- dependency-name: google-auth-library
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Author: dependabot[bot]

scripts/gcb2slack/package-lock.json

@@ -6,6 +6,6 @@
   "dependencies": {
     "@google-cloud/functions-framework": "^3.3.0",
     "@slack/webhook": "^7.0.2",
-    "google-auth-library": "^9.6.0"
+    "google-auth-library": "^9.6.1"
   }
 }