**What happened**:

With the new Backport providers, when calling `DataflowCreatePythonJobOperator` with an empty `py_rerquirments` Dataflow commands always launch inside a virtualenv.

**What you expected to happen**:

The Dataflow command should run locally.


airflow/providers/google/cloud/hooks/dataflow.py
self,
        dataflow: Any,
        project_number: str,
        location: str,
        poll_sleep: int = 10,
        name: Optional[str] = None,
        job_id: Optional[str] = None,
        num_retries: int = 0,
        multiple_jobs: bool = False
    ) -> None:
        super().__init__()
        self._dataflow = dataflow
        self._project_number = project_number
        self._job_name = name
        self._job_location = location
        self._multiple_jobs = multiple_jobs
        self._job_id = job_id
        self._num_retries = num_retries
        self._poll_sleep = poll_sleep
        self._jobs = None  
    def is_job_running(self) -> bool: