Support converting the mistral-nemo huggingface weights to nemo format
@ericharper @akoumpa  for vis Thanks, I'll have a fix soon. https://github.com/NVIDIA/NeMo/pull/9953 How about the other way around ? :) Nemo to HF for Mistral Instruct and Base
**Is your feature request related to a problem? Please describe.**

Currently the only provided conversion script is https://github.com/NVIDIA/NeMo/blob/main/scripts/checkpoint_converters/convert_mistral_7b_hf_to_nemo.py. This script doesn't support converting the latest https://huggingface.co/mistralai/Mistral-Nemo-Base-2407 model - I encountered the following issues:
* It does not properly process the `head_dim` parameter which results in weight shape mismatch.
* Supporting the above also requires upgrading the transformers package to the latest version, which brings additional issues like `ALBERT_PRETRAINED_MODEL_ARCHIVE_LIST` not defined in `transformers` which was referenced in nemo/collections/nlp/modules/common/huggingface/huggingface_utils.py.
* The tokenizer conversion doesn't seem to be properly handled. It looks for `tokenizer.model` which does not exist for this new model which uses tekken and the tokenizer file is a json.

**Describe the solution you'd like**

* Upgrade transformers package to latest
* Update the mistral conversion script to support the latest mistral nemo model
* Fix the tokenizer conversion