LayoutLMv3 not downloading via official code samples
### System Info

```shell
Used the official code sample for the microsoft/layoutlmv3-base model, but it is not working

Link to code: https://huggingface.co/docs/transformers/main/en/model_doc/layoutlmv3#transformers.LayoutLMv3Model

Error: 


KeyError                                  Traceback (most recent call last)
<ipython-input-17-2e4d79cdf031> in <module>()
      3 import torch
      4 
----> 5 processor = AutoProcessor.from_pretrained("microsoft/layoutlmv3-base")
      6 model = AutoModelForSequenceClassification.from_pretrained("microsoft/layoutlmv3-base")
      7 

2 frames
/usr/local/lib/python3.7/dist-packages/transformers/models/auto/processing_auto.py in from_pretrained(cls, pretrained_model_name_or_path, **kwargs)
    198             )
    199             if tokenizer_config_file is not None:
--> 200                 with open(tokenizer_config_file, encoding="utf-8") as reader:
    201                     config_dict = json.load(reader)
    202 

/usr/local/lib/python3.7/dist-packages/transformers/models/auto/configuration_auto.py in from_pretrained(cls, pretrained_model_name_or_path, **kwargs)
    698                     " set the option `trust_remote_code=True` to remove this error."
    699                 )
--> 700             if kwargs.get("revision", None) is None:
    701                 logger.warning(
    702                     "Explicitly passing a `revision` is encouraged when loading a configuration with custom code to "

/usr/local/lib/python3.7/dist-packages/transformers/models/auto/configuration_auto.py in __getitem__(self, key)
    407     A dictionary that lazily load its values when they are requested.
    408     """
--> 409 
    410     def __init__(self, mapping):
    411         self._mapping = mapping

KeyError: 'layoutlmv3'
```
```


### Who can help?

@Lysan

### Information

- [X] The official example scripts
- [ ] 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

https://colab.research.google.com/drive/11aIci0c_UuId5BK2-U6QwZgEKE3ran9I?usp=sharing

### Expected behavior

```shell
The model downloads and executes with the same behaviour as described on HF
```

I believe LayoutLM-v3 is not in an official release yet, so you'll need to install from source in order to use it for now.<|||||>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.