Delete invalid build2update rows before migration (#3395)

The updateid column did not have a foreign-key constraint, so it's
possible for records to exist in the build2update table without a
corresponding record in the buildupdate table.

Author: williamjallen

database/migrations/2026_01_15_143405_drop_build2update_table.php

@@ -5,6 +5,8 @@
 return new class extends Migration {
     public function up(): void
     {
+        DB::delete('DELETE FROM build2update WHERE NOT EXISTS (SELECT 1 FROM buildupdate WHERE build2update.updateid = buildupdate.id)');
+
         DB::statement('ALTER TABLE build ADD COLUMN updateid bigint');
         DB::statement('ALTER TABLE build ADD FOREIGN KEY (updateid) REFERENCES buildupdate(id) ON DELETE SET NULL');