Typo in Google Cloud Storage sensor: airflow/providers/google/cloud/sensors/gcs/GCSObjectsWithPrefixExistenceSensor

The word _With_ is spelled incorrectly. It should be: GCSObjects**With**PrefixExistenceSensor

**Apache Airflow version**: 2.0.0
**Environment**:
- **Cloud provider or hardware configuration**: Google Cloud
- **OS** (e.g. from /etc/os-release): Mac OS BigSur






tests/always/test_project_structure.py
def test_no_illegal_suffixes(self):
        illegal_suffixes = ["_operator.py", "_hook.py", "_sensor.py"]
        files = itertools.chain(
            *[
                glob.glob(f"{ROOT_FOLDER}/{part}/providers/**/{resource_type}/*.py", recursive=True)
                for resource_type in ["operators", "hooks", "sensors", "example_dags"]
                for part in ["airflow", "tests"]
            ]
        )
        invalid_files = [f for f in files if any(f.endswith(suffix) for suffix in illegal_suffixes)]
        assert [] == invalid_files