chore(migrations): Drop unused index in Incident table (#58449)

This PR gets rid of the index on `id, date_added`. This was originally
added in #58207 to make a query in #58032 more efficient, however, after
it was added, we determined that it was still really slow. We'll be
using a different approach, so this one is no longer needed.

Author: isabellaenriquez

migrations_lockfile.txt

@@ -9,5 +9,5 @@ feedback: 0003_feedback_add_env
 hybridcloud: 0005_add_missing_org_integration_scope
 nodestore: 0002_nodestore_no_dictfield
 replays: 0003_add_size_to_recording_segment
-sentry: 0576_add_missing_org_integration_scope
+sentry: 0577_drop_latest_incident_index
 social_auth: 0002_default_auto_field

src/sentry/incidents/models.py

@@ -203,10 +203,7 @@ class Meta:
         app_label = "sentry"
         db_table = "sentry_incident"
         unique_together = (("organization", "identifier"),)
-        index_together = (
-            ("alert_rule", "type", "status"),
-            ("id", "date_added"),
-        )
+        index_together = (("alert_rule", "type", "status"),)
 
     @property
     def current_end_date(self):

src/sentry/migrations/0577_drop_latest_incident_index.py

@@ -0,0 +1,30 @@
+# Generated by Django 3.2.20 on 2023-10-19 15:50
+
+from django.db import migrations
+
+from sentry.new_migrations.migrations import CheckedMigration
+
+
+class Migration(CheckedMigration):
+    # This flag is used to mark that a migration shouldn't be automatically run in production. For
+    # the most part, this should only be used for operations where it's safe to run the migration
+    # after your code has deployed. So this should not be used for most operations that alter the
+    # schema of a table.
+    # Here are some things that make sense to mark as dangerous:
+    # - Large data migrations. Typically we want these to be run manually by ops so that they can
+    #   be monitored and not block the deploy for a long period of time while they run.
+    # - Adding indexes to large tables. Since this can take a long time, we'd generally prefer to
+    #   have ops run this and not block the deploy. Note that while adding an index is a schema
+    #   change, it's completely safe to run the operation after the code has deployed.
+    is_dangerous = False
+
+    dependencies = [
+        ("sentry", "0576_add_missing_org_integration_scope"),
+    ]
+
+    operations = [
+        migrations.AlterIndexTogether(
+            name="incident",
+            index_together={("alert_rule", "type", "status")},
+        ),
+    ]