ref(hc): Enable indexes for new actor columns (#46847)

Offline migration to enable indexes on new Actor columns.

migrations_lockfile.txt

@@ -6,5 +6,5 @@ To resolve this, rebase against latest master and regenerate your migration. Thi
 will then be regenerated, and you should be able to merge without conflicts.
 
 nodestore: 0002_nodestore_no_dictfield
-sentry: 0398_actor_fk_inversion
+sentry: 0399_enable_indexes_for_actor_fks
 social_auth: 0001_initial

src/sentry/migrations/0399_enable_indexes_for_actor_fks.py

@@ -0,0 +1,48 @@
+# Generated by Django 2.2.28 on 2023-04-04 00:52
+
+import django.db.models.deletion
+from django.db import migrations
+
+import sentry.db.models.fields.foreignkey
+import sentry.db.models.fields.hybrid_cloud_foreign_key
+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 = True
+
+    dependencies = [
+        ("sentry", "0398_actor_fk_inversion"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="actor",
+            name="team",
+            field=sentry.db.models.fields.foreignkey.FlexibleForeignKey(
+                null=True,
+                on_delete=django.db.models.deletion.CASCADE,
+                db_constraint=False,
+                related_name="actor_from_team",
+                to="sentry.Team",
+                unique=False,
+            ),
+        ),
+        migrations.AlterField(
+            model_name="actor",
+            name="user_id",
+            field=sentry.db.models.fields.hybrid_cloud_foreign_key.HybridCloudForeignKey(
+                "sentry.User", db_index=True, null=True, on_delete="CASCADE", unique=False
+            ),
+        ),
+    ]

src/sentry/models/actor.py

@@ -77,13 +77,13 @@ class Actor(Model):
         )
     )
     user_id = HybridCloudForeignKey(
-        settings.AUTH_USER_MODEL, on_delete="CASCADE", db_index=False, unique=False, null=True
+        settings.AUTH_USER_MODEL, on_delete="CASCADE", db_index=True, unique=False, null=True
     )
     team = FlexibleForeignKey(
         "sentry.Team",
         related_name="actor_from_team",
-        db_index=False,
         db_constraint=False,
+        db_index=True,
         unique=False,
         null=True,
         on_delete=models.CASCADE,