[#2695] Update trigger for the host-instructor introduction

When recruitment is opened or closed, the strategy for host-instructor introduction is run.

amy/recruitment/views.py

@@ -17,6 +17,10 @@
 import django_rq
 from flags.views import FlaggedViewMixin
 
+from emails.actions.host_instructors_introduction import (
+    host_instructors_introduction_strategy,
+    run_host_instructors_introduction_strategy,
+)
 from emails.signals import (
     admin_signs_instructor_up_for_workshop_signal,
     instructor_confirmed_for_workshop_signal,
@@ -522,6 +526,12 @@ def close_recruitment(self) -> HttpResponse:
                 f"Successfully closed recruitment {self.object}.",
             )
 
+        run_host_instructors_introduction_strategy(
+            host_instructors_introduction_strategy(self.object.event),
+            self.request,
+            self.object.event,
+        )
+
         return HttpResponseRedirect(self.get_success_url())
 
     @staticmethod
@@ -544,6 +554,12 @@ def reopen_recruitment(self) -> HttpResponse:
                 self.request, f"Successfully re-opened recruitment {self.object}."
             )
 
+        run_host_instructors_introduction_strategy(
+            host_instructors_introduction_strategy(self.object.event),
+            self.request,
+            self.object.event,
+        )
+
         return HttpResponseRedirect(self.get_success_url())
 
     def form_valid(self, form: BaseForm) -> HttpResponse: