ref(migration): Mark deprecated is_default in savedsearch nullable (#40755)

Co-authored-by: getsantry[bot] <66042841+getsantry[bot]@users.noreply.github.com>

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: 0335_cleanup_old_savedsearches
+sentry: 0336_mark_deprecated_savedsearch_is_default_nullable
 social_auth: 0001_initial

src/sentry/migrations/0336_mark_deprecated_savedsearch_is_default_nullable.py

@@ -0,0 +1,36 @@
+# Generated by Django 2.2.28 on 2022-11-01 00:53
+
+from django.db import migrations, models
+
+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
+
+    # This flag is used to decide whether to run this migration in a transaction or not. Generally
+    # we don't want to run in a transaction here, since for long running operations like data
+    # back-fills this results in us locking an increasing number of rows until we finally commit.
+    atomic = False
+
+    dependencies = [
+        ("sentry", "0335_cleanup_old_savedsearches"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="savedsearch",
+            name="is_default",
+            field=models.BooleanField(default=False, null=True),
+        ),
+    ]

src/sentry/models/savedsearch.py

@@ -62,7 +62,7 @@ class SavedSearch(Model):
     # are not queried on or in use anywhere, after creating a migration to
     # remove old rows, we should remove these.
     project = FlexibleForeignKey("sentry.Project", null=True)
-    is_default = models.BooleanField(default=False)
+    is_default = models.BooleanField(default=False, null=True)
 
     class Meta:
         app_label = "sentry"