Decouple remote logging config from core

[jason810496]

• related: Decouple remote logging configuration from core airflow #65281
• related: Clarify logging_config_class and deprecate ES/OS implicit REMOTE_TASK_LOG registration #66994

Why

Decouple remote logging config from hardcoded airflow-core/src/airflow/config_templates/airflow_local_settings.py by introducing new remote-logging field for ProvidersManager. Add shared resolve_remote_task_log it, so core and the Task SDK
share one implementation of the precedence rule.

What

Single shared resolver resolve_remote_task_log with an explicit three-tier precedence:

1. User-defined [logging] logging_config_class module exporting
   REMOTE_TASK_LOG / DEFAULT_REMOTE_CONN_ID.
2. ProvidersManager scheme dispatch on [logging] remote_base_log_folder,
   instantiated via the provider class's from_config() classmethod.
3. Legacy attr-path fallback against
   airflow.config_templates.airflow_local_settings (transitional).

airflow.logging_config.load_logging_config is deprecated and split into

• _get_logging_config() (logging dict)
• _load_logging_config() (remote handler, lazy)
• configure_logging no longer eagerly resolves the remote handler.

Next step to deprecate hardcoded airflow_local_settings.py

1. Provider migration: Migrate the logic from airflow_local_settings.py as from_config method for each current supported RemoteIO.

class S3RemoteLogIO(LoggingMixin):
    @classmethod
    def from_config(cls) -> "S3RemoteLogIO":
        from airflow.providers.common.compat.sdk import conf

        # provider-specific `conf` validation or custom logic
        return cls(
            base_log_folder=conf.get("logging", "base_log_folder"),
            remote_base=conf.get("logging", "remote_base_log_folder"),
            delete_local_copy=conf.getboolean("logging", "delete_local_logs"),
        )

2. Raise deprecation warning for each if/else branch after the corresponding RemoteIO.from_config is added.

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Was generative AI tooling used to co-author this PR?

• Yes, with help of Claude Code (Opus 4.7) following the guidelines

[jscheffl]

Looks clean and good to me - except some small comments. Another pair of eyes would be good prior merge.