Cherry pick `add huggingface-based tokenizer support for mixtral HF -> .nemo (11572)` into `r2.1.0`
<!-- pylint-output-strict-mode-false -->

beep boop 🤖: 🙏 The following files have warnings. In case you are familiar with these, please try helping us to improve the code base.

---

Your code was analyzed with PyLint. The following annotations have been identified:

```
************* Module convert_mixtral_hf_to_nemo
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:477:0: C0301: Line too long (146/119) (line-too-long)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:52:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:80:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:120:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:167:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:175:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:191:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:204:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:244:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:258:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:399:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:412:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:468:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:520:0: C0116: Missing function or method docstring (missing-function-docstring)

-----------------------------------
Your code has been rated at 9.59/10
```

---

Thank you for improving NeMo's documentation! <!-- pylint-output-strict-mode-false -->

beep boop 🤖: 🙏 The following files have warnings. In case you are familiar with these, please try helping us to improve the code base.

---

Your code was analyzed with PyLint. The following annotations have been identified:

```
************* Module convert_mixtral_hf_to_nemo
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:477:0: C0301: Line too long (146/119) (line-too-long)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:52:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:80:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:120:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:167:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:175:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:191:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:204:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:244:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:258:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:399:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:412:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:468:0: C0116: Missing function or method docstring (missing-function-docstring)
scripts/checkpoint_converters/convert_mixtral_hf_to_nemo.py:520:0: C0116: Missing function or method docstring (missing-function-docstring)

-----------------------------------
Your code has been rated at 9.59/10
```

---

Thank you for improving NeMo's documentation! Already merged cherrypick in different PR
beep boop [🤖]: Hi @dimapihtar 👋,
    
    we've cherry picked #11572 into  for you! 🚀
    
    Please review and approve this cherry pick by your convenience!