[BUG] Evaluation set local data import failed

### 📋 CheckList

- [x] I have searched existing issues to avoid duplicates
- [x] I am using a recently maintained version of Coze Loop
- [x] I have provided all required information
- [x] I understand this is a bug report and not a feature request
- [x] I have submitted this report in English (otherwise it will not be processed)

### 🐛 Bug Description

When I tried to import a local file named 111.xlsx using the local import method in the "Add Data" section, the page kept loading and failed to import the data correctly.

I checked the `dataset_io_jobs` API, and the error returned was "message": "unknown file format: \u003cUNSET\u003e".

The response is as follows：
`{
"code": 0,
"job": {
"app_id": 0,
"created_at": "1768379901000",
"created_by": "7595089854925373441",
"dataset_id": "7595090469839699969",
"ended_at": null,
"errors": [
{
"details": [
{
"message": "unknown file format: \u003cUNSET\u003e"
},
{
"message": "unknown file format: \u003cUNSET\u003e"
}
],
"error_count": 0,
"type": 100
}
],
"field_mappings": [
{
"source": "input",
"target": "input"
}
],
"id": "7595133844693450753",
"job_type": 1,
"option": {
"overwrite_dataset": false
},
"progress": {
"added": "0",
"processed": "0",
"sub_progresses": [
{
"added": "0",
"name": "",
"processed": "0",
"total": null
}
],
"total": "0"
},
"source": {
"file": {
"compress_format": 0,
"format": 4,
"path": "7595089855009259521/aSJARmib6v9dttnagV4Sn/111.xlsx",
"provider": 5
}
},
"space_id": "7595089855009259521",
"started_at": "1768379902000",
"status": 2,
"target": {
"dataset": {
"dataset_id": "7595090469839699969",
"space_id": null,
"version_id": null
}
},
"updated_at": "1768379911000",
"updated_by": "7595089854925373441"
},
"msg": ""
}`

### 🔄 Steps to Reproduce

1. Create the local file 111.xlsx and add some data.
2. Create an evaluation set, import the evaluation data, and select local import when adding data.
3. In the pop-up dialog box, I selected the local data file 111.xlsx and clicked the import button.

### ✅ Expected Behavior

The data in the local file will be added to the evaluation .

### ❌ Actual Behavior

import data failed

### 🚨 Severity

None

### 🔧 Component

None

### 💻 Environment

_No response_

### 🔧 Go Environment

_No response_

### 📋 Logs

```shell

```

### 📝 Additional Context

_No response_