fix: add issues trigger to issue-monster workflow (#338)

* Initial plan

* fix: add issues trigger to issue-monster workflow

Co-authored-by: Mossaka <5447827+Mossaka@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Mossaka <5447827+Mossaka@users.noreply.github.com>

Author: Copilot

.github/workflows/issue-monster.lock.yml

@@ -2,6 +2,8 @@
 name: Issue Monster
 description: The Cookie Monster of issues - assigns issues to Copilot agents one at a time
 on:
+  issues:
+    types: [opened]
   workflow_dispatch:
   schedule: every 1h
   skip-if-match: