`AddCastNode` in `insert_cast_transformer.cc` sets invalid dtype `-1`

### Describe the issue

ORT executing the fp16 model

```
<
ir_version: 3,
opset_import: ["" : 1]
>
node_graph (float16[2,3] input0) => (float16[2,3] output0) {
output0 = RandomNormalLike (input0)
}
```

with CPU will produce an error

`onnxruntime.capi.onnxruntime_pybind11_state.InvalidGraph: [ONNXRuntimeError] : 10 : INVALID_GRAPH : This is an invalid model. In Node, ("InsertedCast_input0", Cast, "", -1) : ("input0": tensor(float16),) -> ("InsertedCast_input0": tensor(float),) , Error Mismatched attribute type in 'InsertedCast_input0 : to'`

It appears `to_type` was somehow set to `-1` in https://github.com/microsoft/onnxruntime/blob/3c2d52a995954cd9ce24b2831060c4326ab18e1c/onnxruntime/core/optimizer/insert_cast_transformer.cc#L28C23-L47

### To reproduce

As above

### Urgency

_No response_

### Platform

Linux

### OS Version

Ubuntu 22.04

### ONNX Runtime Installation

Released Package

### ONNX Runtime Version or Commit ID

1.15.0

### ONNX Runtime API

Python

### Architecture

X64

### Execution Provider

Default CPU

### Execution Provider Library Version

_No response_