fix: MRO Issue in operator/clickhouse_dbapi

[rohithreddykota]

This PR addresses a method resolution order (MRO) issue in the ClickHouse.*Operator implementations.

For example ClickHouseBranchSQLOperator, due to the current inheritance order, parameters intended for the sql.BranchSQLOperator (such as follow_task_ids_if_true, follow_task_ids_if_false, and parameters) are not being correctly processed. This results in an “Invalid arguments” error when the operator is instantiated.

Background

The operator is defined as follows:

class ClickHouseBranchSQLOperator(
    sql.BranchSQLOperator,
    ClickHouseBaseDbApiOperator,
):
    pass

Because of Python’s MRO, the init method from ClickHouseBaseDbApiOperator (or its parent, BaseSQLOperator) is encountered before sql.BranchSQLOperator.init. As a result, any branch-specific parameters are not recognized, leading to failures when those parameters are passed during instantiation.

[bryzgaloff]

Hi @rohithreddykota, thank you for your contribution!

Would it be possible to demonstrate the incorrect MRO through the tests first? This functionality is indeed not yet covered by tests: https://github.com/bryzgaloff/airflow-clickhouse-plugin/blob/master/tests/unit/operators/test_clickhouse_dbapi.py

From my understanding of how MRO works, ClickHouseBranchSQLOperator(...) should first call BranchSQLOperator's __init__, then ClickHouseBaseDbApiOperator's, followed by their parent classes. This is the intended order — the goal is to pass BranchSQLOperator-specific arguments first, while any unused ones should flow through the superclass chain. Do I miss something here?