Add workflow that will send a notification to horreum-plugin project.

[whitingjr]

Fixes Issue

fixes #2056

Changes proposed

[x] - Add a workflow to send a notification.

• [x] My code follows the code style of this project.
• [ ] My change requires changes to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] All new and existing tests passed.
• [ ] Ensure the Personal Access Token is stored as a secret on this repository