Add fail_on_file_not_exist option to SFTPToS3Operator

[Guaqamole]

Fixes: #40576

I added fail_on_file_not_exist param to SFTPToS3Operator so that user can configure the parameter and operator will not fail in case of sftp file not exist.

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Here's the test result ran in my local environment.

you can see the dag does not fail with fail_on_file_not_exist but still shows logs that the file does not exist.

sftp_to_s3_dag.py

from airflow import DAG
from airflow.providers.amazon.aws.transfers.sftp_to_s3 import SFTPToS3Operator
from datetime import datetime, timedelta

default_args = {
    "owner": "airflow",
    "retries": 1,
    "retry_delay": timedelta(minutes=1),
}

with DAG(
    dag_id="sftp_to_s3_example",
    default_args=default_args,
    description="Transfer a file from SFTP to S3",
    schedule_interval=None,
    start_date=datetime(2023, 1, 1),
    catchup=False,
    tags=["example", "sftp", "s3"],
) as dag:
    transfer_file = SFTPToS3Operator(
        task_id="transfer_file",
        sftp_conn_id="sftp_default",
        sftp_path="/Users/john/test.mv.dba", 
        s3_conn_id="aws_conn",
        s3_bucket="airflow",
        s3_key="test/test.mv.db",
        fail_on_file_not_exist=False,
    )

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