Fix tokenizer file caching where torch.distributed may not be initialized yet
Other ranks with multi-node training may reach this code before rank 0 and torch.distributed has not been initialized and does not wait for download

# What does this PR do ?

Fix to be flexible to download by other ranks if not initialized and errors looking for file that does not exist yet

**Collection**: [NLP]

# Changelog 
- Add specific line by line info of high level changes in this PR.

# Usage

```
  File "/opt/NeMo/nemo/collections/nlp/modules/common/tokenizer_utils.py", line 207, in get_nmt_tokenizer
    return get_tokenizer(tokenizer_name=model_name, vocab_file=vocab_file, merges_file=merges_file)
  File "/opt/NeMo/nemo/collections/nlp/modules/common/tokenizer_utils.py", line 134, in get_tokenizer
    return AutoTokenizer(
  File "/opt/NeMo/nemo/collections/common/tokenizers/huggingface/auto_tokenizer.py", line 81, in __init__
    raise ValueError(
ValueError: Unable to instantiate HuggingFace AUTOTOKENIZER for gpt2. Exception: Unable to load vocabulary from file. Please check that the provided vocabulary is accessible and not corrupted.
[NeMo I 2023-07-17 16:42:10 megatron_init:297] Rank 0 has embedding rank: 0
23-07-17 16:42:10 - PID:215 - rank:(0, 0, 0, 0) - microbatches.py:39 - INFO - setting number of micro-batches to constant 1
[NeMo I 2023-07-17 16:42:10 tokenizer_utils:204] Getting Megatron tokenizer for pretrained model name: megatron-gpt-345m, custom vocab file: None, and merges file: None
[NeMo I 2023-07-17 16:42:10 megatron_utils:208] Downloading from https://s3.amazonaws.com/models.huggingface.co/bert/gpt2-vocab.json to /mount/workspace/megatron/megatron-gpt-345m_vocab
[NeMo I 2023-07-17 16:42:10 megatron_utils:208] Downloading from https://s3.amazonaws.com/models.huggingface.co/bert/gpt2-merges.txt to /mount/workspace/megatron/megatron-gpt-345m_merges
[NeMo I 2023-07-17 16:42:10 tokenizer_utils:130] Getting HuggingFace AutoTokenizer with pretrained_model_name: gpt2, vocab_file: /mount/workspace/megatron/megatron-gpt-345m_vocab, merges_files: /mount/workspace/megatron/megatron-gpt-345m_merges, special_tokens_dict: {}, and use_fast: False
```

**PR Type**:
- [ ] New Feature
- [x] Bugfix
- [ ] Documentation

## Who can review?

Anyone in the community is free to review the PR once the checks have passed. 
[Contributor guidelines](https://github.com/NVIDIA/NeMo/blob/main/CONTRIBUTING.md) contains specific people who can review PRs to various areas.

# Additional Information
* Related to #7016 
