Cloud SQL — CloudSQLImportInstanceOperator / CloudSQLExportInstanceOperator 409 operationInProgress on parallel tasks against the same instanc

Providers ### Apache Airflow version 2.10.3 or 3.2.0 + ### What happened and how to reproduce it? # Cloud SQL — `CloudSQLImportInstanceOperator` / `CloudSQLExportInstanceOperator` 409 `operationInProgress` on parallel tasks against the same instance ## Problem Two `CloudSQLImportInstanceOperator` tasks against the same instance, no dependency between them → fan out in parallel → one succeeds, the other fails in <2s with HTTP 409 / `operationInProgress`. Same race on `CloudSQLExportInstanceOperator` and on IMPORT+EXPORT mixed: Cloud SQL serializes admin ops per instance. Provider does not retry. No sensor in the provider waits for the instance to be idle. ## Versions | Component | Version | | --- | --- | | Apache Airflow | 2.10.3 | | apache-airflow-providers-google | 10.22.0 | | apache-airflow-providers-postgres | 5.11.1 | | Cloud SQL instance | `my-cloudsql-pg` (PostgreSQL 16, `us-central1`) | | Executor | LocalExecutor | | Python | 3.12.7 | Also reproduces on Airflow 3.2.0 + providers-google 19.5.0. ## Reproduction DAG ```python from datetime import datetime from pathlib import Path from airflow import DAG from airflow.models.param import Param from airflow.providers.google.cloud.operators.cloud_sql import ( CloudSQLImportInstanceOperator, ) from airflow.providers.postgres.operators.postgres import PostgresOperator INIT_SQL_PATH = Path(__file__).resolve().parent / "init_tables.sql" with DAG( dag_id="reproduce_409_cloudsql_import", start_date=datetime(2024, 1, 1), schedule=None, catchup=False, params={ "PROJECT_ID": Param(default="CHANGE_ME", type="string"), "INSTANCE": Param(default="CHANGE_ME", type="string"), "GCS_BUCKET": Param(default="CHANGE_ME", type="string"), "DB_NAME": Param(default="airflow_db", type="string"), }, render_template_as_native_obj=True, ) as dag: create_tables = PostgresOperator( task_id="create_tables", postgres_conn_id="cloudsql_pg", sql=INIT_SQ…