### Apache Airflow Provider(s)

sftp

### Versions of Apache Airflow Providers

apache-airflow-providers-sftp==4.1.0

### Apache Airflow version

2.4.2 Python 3.10

### Operating System

Debian 11 (Official docker image)

### Deployment

Docker-Compose

### Deployment details

Base image is apache/airflow:2.4.2-python3.10


### What happened

When combining Taskflow API and SFTPOperator, it throws an exception that didn't happen with apache-airflow-providers-sftp 4.0.0

### What you think should happen instead

The DAG should work as expected

### How to reproduce

```python
import pendulum

from airflow import DAG
from airflow.decorators import task
from airflow.providers.sftp.operators.sftp import SFTPOperator

with DAG(
    "example_sftp",
    schedule="@once",
    start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
    catchup=False,
    tags=["example"],
) as dag:

    @task
    def get_file_path():
        return "test.csv"

    local_filepath = get_file_path()

    upload = SFTPOperator(
        task_id=f"upload_file_to_sftp",
        ssh_conn_id="sftp_connection",
        local_filepath=local_filepath,
        remote_filepath="test.csv",
    )
```

### Anything else

```logs
[2022-10-27T15:21:38.106+0000]` {logging_mixin.py:120} INFO - [2022-10-27T15:21:38.102+0000] {dagbag.py:342} ERROR - Failed to import: /opt/airflow/dags/test.py
Traceback (most recent call last):
  File "/home/airflow/.local/lib/python3.10/site-packages/airflow/models/dagbag.py", line 338, in parse
    loader.exec_module(new_module)
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/opt/airflow/dags/test.py", line 21, in <module>
    upload = SFTPOperator(
  File "/home/airflow/.local/lib/python3.10/site-packages/airflow/models/baseoperator.py", line 408, in apply_defaults
    result = func(self, **kwargs, default_args=default_args)
  File "/home/airflow/.local/lib/python3.10/site-packages/airflow/providers/sftp/operators/sftp.py", line 116, in __init__
    if len(self.local_filepath) != len(self.remote_filepath):
TypeError: object of type 'PlainXComArg' has no len()
```

It looks like the offending code was introduced in commit 5f073e38dd46217b64dbc16d7b1055d89e8c3459

### Are you willing to submit PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

def setup_method(self):
        hook = SSHHook(ssh_conn_id="ssh_default")
        hook.no_host_key_check = True
        self.hook = hook
        sftp_hook = SFTPHook(ssh_conn_id="ssh_default")
        sftp_hook.no_host_key_check = True
        self.sftp_hook = sftp_hook
        self.test_dir = "/tmp"
        self.test_local_dir = "/tmp/tmp2"
        self.test_remote_dir = "/tmp/tmp1"
        self.test_local_filename = "test_local_file"
        self.test_remote_filename = "test_remote_file"
        self.test_remote_file_content = (
            b"This is remote file content \n which is also multiline "
            b"another line here \n this is last line. EOF"
        )
        self.test_local_filepath = f"{self.test_dir}/{self.test_local_filename}"
        
        self.test_local_filepath_int_dir = f"{self.test_local_dir}/{self.test_local_filename}"
        self.test_remote_filepath = f"{self.test_dir}/{self.test_remote_filename}"
        
        self.test_remote_filepath_int_dir = f"{self.test_remote_dir}/{self.test_remote_filename}"
    def teardown_method(self):