Add missing migration (#28827)

Missed from #28498

models/migrations/migrations.go

@@ -552,6 +552,8 @@ var migrations = []Migration{
 	NewMigration("Add Index to pull_auto_merge.doer_id", v1_22.AddIndexToPullAutoMergeDoerID),
 	// v283 -> v284
 	NewMigration("Add combined Index to issue_user.uid and issue_id", v1_22.AddCombinedIndexToIssueUser),
+	// v284 -> v285
+	NewMigration("Add ignore stale approval column on branch table", v1_22.AddIgnoreStaleApprovalsColumnToProtectedBranchTable),
 }
 
 // GetCurrentDBVersion returns the current db version