**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
"""
        Cancels current job
        """
        jobs = self._get_current_jobs()
        batch = self._dataflow.new_batch_http_request()
        job_ids = [job['id'] for job in jobs]
        self.log.info("Canceling jobs: %s", ", ".join(job_ids))
        for job_id in job_ids:
            batch.add(
                self._dataflow.projects().locations().jobs().update(
                    projectId=self._project_number,
                    location=self._job_location,
                    jobId=job_id,
                    body={
                        "requestedState": DataflowJobStatus.JOB_STATE_CANCELLED
                    }
                )
            )
        batch.execute()
class _DataflowRunner(LoggingMixin):