feat: add idempotent producer publication

tests/test_migrations.py

@@ -24,13 +24,14 @@ class DatasourceMigrationTests(unittest.TestCase):
             try:
                 with engine.connect() as connection:
                     self.assertIn(
-                        "f3a8d2c7b1e0",
+                        "c4e9f1a7d2b6",
                         set(MigrationContext.configure(connection).get_current_heads()),
                     )
                     self.assertEqual(
                         {
                             "datasource_catalogue",
                             "datasource_materializations",
+                            "datasource_publications",
                             "datasource_stages",
                         },
                         {