### Overview
Some Executors, currently a subset of the local Executors, run in a single threaded fashion and have certain limitations and requirements, many of which are hardcoded. To add a new single threaded Executor would require changes to core Airflow code.
Note: This coupling often shows up with SQLite compatibility checks since it does not support multiple connections.
### Examples
- **2a**) SQLite check done in configuration.py: https://github.com/apache/airflow/blob/26f94c5370587f73ebd935cecf208c6a36bdf9b6/airflow/configuration.py#L412-L419
- **2b**) When running in standalone mode SQLite compatibility is checked: https://github.com/apache/airflow/blob/26f94c5370587f73ebd935cecf208c6a36bdf9b6/airflow/cli/commands/standalone_command.py#L160-L165
- **2c**) Sensors in `poke` mode can block execution of DAGs when running with single process Executors, currently hardcoded to DebugExecutor (although should also include SequentialExecutor): https://github.com/apache/airflow/blob/27e2101f6ee5567b2843cbccf1dca0b0e7c96186/airflow/sensors/base.py#L243
### Proposal
A static method or attribute on the Executor class which can be checked by core code.

There is a precedent already set with the `supports_ad_hoc_ti_run` attribute, see:
https://github.com/apache/airflow/blob/fb741fd87254e235f99d7d67e558dafad601f253/airflow/executors/kubernetes_executor.py#L435 https://github.com/apache/airflow/blob/26f94c5370587f73ebd935cecf208c6a36bdf9b6/airflow/www/views.py#L1735-L1737
super().__init__()
        self._job_id: int | None = None
        self.celery_executor = celery_executor
        self.kubernetes_executor = kubernetes_executor
        self.kubernetes_executor.kubernetes_queue = self.KUBERNETES_QUEUE
    @property
    def queued_tasks(self) -> dict[TaskInstanceKey, QueuedTaskInstanceType]:
        """Return queued tasks from celery and kubernetes executor."""
        queued_tasks = self.celery_executor.queued_tasks.copy()
        queued_tasks.update(self.kubernetes_executor.queued_tasks)
        return queued_tasks
    @property
    def running(self) -> set[TaskInstanceKey]:
        """Return running tasks from celery and kubernetes executor."""
        return self.celery_executor.running.union(self.kubernetes_executor.running)
    @property
    def job_id(self) -> int | None:
        """
        Inherited attribute from BaseExecutor.
        Since this is not really an executor, but a wrapper of executors
        we implemented it as property, so we can have custom setter.
        """
        return self._job_id
    @job_id.setter
    def job_id(self, value: int | None) -> None: