Fix mismatched AirflowConfigException in celery and edge3

[FrankYang0529]

Why

• Update conf imports in providers to use airflow.sdk.configuration #60000 moved providers to from airflow.providers.common.compat.sdk import conf. celery and edge3 took the new conf but left AirflowConfigException coming from airflow.exceptions.
• The compat conf resolves to the Task SDK parser, which raises airflow.sdk._shared.configuration.exceptions.AirflowConfigException. The handlers name airflow.exceptions.AirflowConfigException, so they never catch what the parser raises.
• default_celery.py needs both classes in the handler, because get_default_celery_config() also receives core's ExecutorConf on the multi-team path.

How

• The edge3 plugin and celery_command.py only ever see the compat conf, so AirflowConfigException now comes from the same compat import line.
• get_default_celery_config() gets the compat conf at module scope and core's ExecutorConf on the multi-team path. Those two raise different classes, so the handler in default_celery.py catches both.

Verification

• uv run --project providers/celery pytest "providers/celery/tests/unit/celery/executors/test_celery_executor.py" "providers/celery/tests/unit/celery/cli/test_celery_command.py" "providers/edge3/tests/unit/edge3/plugins/test_edge_executor_plugin.py" -v

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