Onnx CLIP Model outputs "Shape mismatch" warining on inference
### System Info

- `transformers` version: 4.23.1
- Platform: Linux-5.10.102.1-microsoft-standard-WSL2-x86_64-with-glibc2.29
- Python version: 3.8.10
- Huggingface_hub version: 0.10.1
- PyTorch version (GPU?): 1.12.1+cu116 (True)
- Tensorflow version (GPU?): not installed (NA)
- Flax version (CPU?/GPU?/TPU?): not installed (NA)
- Jax version: not installed
- JaxLib version: not installed
- Using GPU in script?: No
- Using distributed or parallel set-up in script?: No

### Who can help?

@patil-suraj

### Information

- [ ] The official example scripts
- [X] My own modified scripts

### Tasks

- [X] An officially supported task in the `examples` folder (such as GLUE/SQuAD, ...)
- [ ] My own task or dataset (give details below)

### Reproduction

1. Convert clip to onnx `python -m transformers.onnx -m openai/clip-vit-base-patch32 onnx/`
2. Try to inference

```
import transformers
import onnxruntime
import numpy as np
from PIL import Image
import torch
model_path = "onnx/model.onnx"
example_image = "swatch01.png"
session = onnxruntime.InferenceSession(model_path)
processor = transformers.CLIPProcessor.from_pretrained("openai/clip-vit-base-patch32")
labels = [
            "a close up of a person's eye photo",
            "a person's arm with a bunch of lipstick swatches on it",
# (snip)
]
img = Image.open(example_image)
inputs = processor(text=candidate_labels, images=img,
 return_tensors="np", padding=True)
ort_inputs = {
    "input_ids": inputs["input_ids"],
    "attention_mask": inputs["attention_mask"],
    "pixel_values": inputs["pixel_values"]
}
ort_outputs = session.run(None, ort_inputs)
```

3. It work but some warinings:
```
2022-10-27 09:23:18.299824270 [W:onnxruntime:, execution_frame.cc:594 AllocateMLValueTensorPreAllocateBuffer] Shape mismatch attempting to re-use buffer. {42,512} != {1,512}. Validate usage of dim_value (values should be > 0) and dim_param (all values with the same string should equate to the same size) in shapes in the model.
2022-10-27 09:23:18.300383069 [W:onnxruntime:, execution_frame.cc:594 AllocateMLValueTensorPreAllocateBuffer] Shape mismatch attempting to re-use buffer. {42,1} != {1,1}. Validate usage of dim_value (values should be > 0) and dim_param (all values with the same string should equate to the same size) in shapes in the model.
```
(`42` is the number of labels)

### Expected behavior

The model work find, but the waring outputs every inference.

cc @lewtun <|||||>This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the [contributing guidelines](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md) are likely to be ignored.