Bump @slack/webhook from 7.0.4 to 7.0.5 in /scripts/gcb2slack (#3754)

Bumps [@slack/webhook](https://github.com/slackapi/node-slack-sdk) from 7.0.4 to 7.0.5.
- [Release notes](https://github.com/slackapi/node-slack-sdk/releases)
- [Commits](https://github.com/slackapi/node-slack-sdk/compare/@slack/[email protected]...@slack/[email protected])

---
updated-dependencies:
- dependency-name: "@slack/webhook"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

scripts/gcb2slack/package-lock.json

@@ -5,7 +5,7 @@
   "main": "index.js",
   "dependencies": {
     "@google-cloud/functions-framework": "^3.4.6",
-    "@slack/webhook": "^7.0.4",
+    "@slack/webhook": "^7.0.5",
     "google-auth-library": "^9.15.1"
   }
 }