[BUG] get_offline_feature ignores `parquet` output file option

### Willingness to contribute

No. I cannot contribute a bug fix at this time.

### Feathr version

0.8.0

### System information

- **OS Platform and Distribution (e.g., Linux Ubuntu 20.0)**: both on Linux Ubuntu 20 and Databricks
- **Python version**: 3.10
- **Spark version, if reporting runtime issue**:

### Describe the problem

get_offline_feature always write into avro regardless of the execution config.

### Tracking information

_No response_

### Code to reproduce bug

Run:
```
get_offline_feature(
execution_configurations=SparkExecutionConfiguration({
"spark.feathr.inputFormat": "parquet",
"spark.feathr.outputFormat": "parquet",
}),
....
)
```
still write file as avro

### What component(s) does this bug affect?

- [ ] `Python Client`: This is the client users use to interact with most of our API. Mostly written in Python.
- [ ] `Computation Engine`: The computation engine that execute the actual feature join and generation work. Mostly in Scala and Spark.
- [ ] `Feature Registry API`: The frontend API layer supports SQL, Purview(Atlas) as storage. The API layer is in Python(FAST API)
- [ ] `Feature Registry Web UI`: The Web UI for feature registry. Written in React