[BUG] "Trigger Breaking Change Notifications" workflow is broken

Describe the bug

This workflow:

https://github.com/NVIDIA/cuvs/blob/7a5cc2282eb1e02ffeb610e8ed21c24a28101ba8/.github/workflows/trigger-breaking-change-alert.yaml#L16-L23

Is failing like this:

file:///home/runner/work/_actions/slackapi/slack-github-action/45a88b9581bfab2566dc881e2cd66d334e621e2c/src/config.js:210
        throw new SlackError(
^
SlackError: Missing input! Either a method or webhook is required to take action.
    at Config.validate (file:///home/runner/work/_actions/slackapi/slack-github-action/45a88b9581bfab2566dc881e2cd66d334e621e2c/src/config.js:210:1)
    at new Config (file:///home/runner/work/_actions/slackapi/slack-github-action/45a88b9581bfab2566dc881e2cd66d334e621e2c/src/config.js:126:1)
    at send (file:///home/runner/work/_actions/slackapi/slack-github-action/45a88b9581bfab2566dc881e2cd66d334e621e2c/src/send.js:12:1)
    at file:///home/runner/work/_actions/slackapi/slack-github-action/45a88b9581bfab2566dc881e2cd66d334e621e2c/src/index.js:9:1
    at __nccwpck_require__.a (file:///home/runner/work/_actions/slackapi/slack-github-action/45a88b9581bfab2566dc881e2cd66d334e621e2c/webpack/runtime/async module:49:1)
    at Object.9722 (file:///home/runner/work/_actions/slackapi/slack-github-action/45a88b9581bfab2566dc881e2cd66d334e621e2c/dist/index.js:47275:21)
    at __nccwpck_require__ (file:///home/runner/work/_actions/slackapi/slack-github-action/45a88b9581bfab2566dc881e2cd66d334e621e2c/webpack/bootstrap:21:1)
    at file:///home/runner/work/_actions/slackapi/slack-github-action/45a88b9581bfab2566dc881e2cd66d334e621e2c/webpack/startup:4:1
    at ModuleJob.run (node:internal/modules/esm/module_job:439:25)
    at node:internal/modules/esm/loader:633:26

(build link)

Steps/Code to reproduce bug

Add the breaking label to any PR.

Expected behavior

Adding the breaking label to a PR should trigger a notification to the internal #swrapids-breaking-change-alerts channel.

Environment details (please complete the following information):

N/A

Additional context

Noticed on #2305

I suspect this is just an issue of a missing secret, missed in the migration to the NVIDIA org because this workflow runs infrequently.