Add custom message to label enforcer

This release just adds a custom message to the label enforcer.

---

From CHANGELOG.md

Changed

• Updated label-enforcer to v3 and added custom message

---

What's Changed

• Add custom messages to label enforcers by @mathomp4 in #302
• Merge develop into main for release by @mathomp4 in #303

Full Changelog: v3.23.0...v3.24.0