Don't use nvidia_torch_version until after None check

[wspear]

What does this PR do ?

There was a crash when nvidia_torch_version came back as None because it was still being used before the None check.

Collection: [NLP]

Changelog

Fixed crash when NVIDIA_PYTORCH_VERSION is not set

Usage

• You can potentially add a usage example below
  Run a anything that exercises this code without NVIDIA_PYTORCH_VERSION set

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PR Type:

• New Feature
• [X ] Bugfix
• Documentation

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Additional Information

• Related to # (issue)
  This is a minor fix. No associated tests or documentation. I tried to keep it simple. Devs may prefer different logic (e.g. an extra none check before the official release check, move the is_official_release_version def inside the None check block, etc)

[github-actions]

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

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

************* Module nemo.collections.nlp.models.language_modeling.megatron_base_model
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:103:0: C0301: Line too long (149/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:111:0: C0301: Line too long (134/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:252:0: C0301: Line too long (125/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:270:0: C0301: Line too long (120/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:345:0: C0301: Line too long (133/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:604:0: C0301: Line too long (123/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:659:0: C0301: Line too long (153/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:831:0: C0301: Line too long (122/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:959:0: C0301: Line too long (121/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:978:0: C0301: Line too long (136/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:1095:0: C0301: Line too long (195/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:1152:0: C0301: Line too long (135/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:1200:0: C0301: Line too long (120/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:1283:0: C0301: Line too long (128/119) (line-too-long)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:329:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:459:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:464:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:697:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:749:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:920:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:1024:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:1258:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:1289:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:1293:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/collections/nlp/models/language_modeling/megatron_base_model.py:1297:4: C0116: Missing function or method docstring (missing-function-docstring)

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