### 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)

#
#
#
from __future__ import annotations
import os
from base64 import b64encode
from unittest import mock
import pytest
from airflow.exceptions import AirflowException
from airflow.models import DAG
from airflow.providers.sftp.hooks.sftp import SFTPHook
from airflow.providers.sftp.operators.sftp import SFTPOperation, SFTPOperator
from airflow.providers.ssh.hooks.ssh import SSHHook
from airflow.providers.ssh.operators.ssh import SSHOperator
from airflow.utils import timezone
from airflow.utils.timezone import datetime
from tests.test_utils.config import conf_vars
DEFAULT_DATE = datetime(2017, 1, 1)
TEST_CONN_ID = "conn_id_for_testing"
class TestSFTPOperator: