Fix never_evict for the "conditional ummute" case

The key phrase from our codebase was:

> # .save() will be called by the caller of this function

But this wasn't the case for the conditionally called path.

Adds data-fixing migration too.

Fix #292

events/migrations/0025_fix_never_evict.py

@@ -0,0 +1,19 @@
+from django.db import migrations
+
+
+def fix_never_evict(apps, schema_editor):
+    Event = apps.get_model("events", "Event")
+    cnt = Event.objects.filter(never_evict=False, turningpoint__isnull=False).update(never_evict=True)
+    if cnt:
+        print(f"\nUpdated {cnt} Event records to set never_evict=True where turningpoint is not null.")
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("events", "0024_remove_event_debug_info"),
+    ]
+
+    operations = [
+        migrations.RunPython(fix_never_evict, migrations.RunPython.noop),
+    ]

ingest/views.py

@@ -459,6 +459,8 @@ class BaseIngestAPIView(View):
                     issue, triggering_event=event,
                     unmute_metadata={"mute_for": {"unmute_after": issue.unmute_after}})
 
+        cls.count_issue_periods_and_act_on_it(issue, event, digested_at)
+
         if event.never_evict:
             # as a sort of poor man's django-dirtyfields (which we haven't adopted for simplicity's sake) we simply do
             # this manually for a single field; we know that if never_evict has been set, it's always been set after the
@@ -470,8 +472,6 @@ class BaseIngestAPIView(View):
         if release.version + "\n" not in issue.events_at:
             issue.events_at += release.version + "\n"
 
-        cls.count_issue_periods_and_act_on_it(issue, event, digested_at)
-
         issue.save()
 
         # intentionally at the end: possible future optimization is to push this out of the transaction (or even use