fix: Enable S3 Upload on local container -> sagemaker endpoint overwrite for TGI, TEI, MMS

[gwang111]

Issue #, if available: N/A

Description of changes:

1. For TGI, TEI, Transformers builder, if not optimized & if overwritting, upload the model artifacts to customer's S3 location
2. Prune deprecated TRANSFORMERS_CACHE env var from the builder code
3. Switch deprecated TRANSFORMERS_OFFLINE env var to HF_HUB_OFFLINE env var

Testing done:

1. Add UT coverage for TGI, TEI, Transformers builder to verify that on overwrite to SAGEMAKER_ENDPOINT mode that S3 upload is set to True
2. Add UT coverage for TGI, TEI, Transformers builder to verify that when going DIRECTLY to SAGEMAKER_ENDPOINT mode that S3 upload is not enabled
3. Add UT coverage for TGI, TEI, Transformers builder to verify that when the model has been optimized that S3 upload is not enabled
4. Add new UT suite for TGI

Verifications:

TGI:

• Verify overwrite
  

TEI

• Verify overwrite
  

MMS

• Verify overwrite
  

Verify no regressions in Optimize

Merge Checklist

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General

• I have read the CONTRIBUTING doc
• I certify that the changes I am introducing will be backward compatible, and I have discussed concerns about this, if any, with the Python SDK team
• I used the commit message format described in CONTRIBUTING
• I have passed the region in to all S3 and STS clients that I've initialized as part of this change.
• I have updated any necessary documentation, including READMEs and API docs (if appropriate)

Tests

• I have added tests that prove my fix is effective or that my feature works (if appropriate)
• I have added unit and/or integration tests as appropriate to ensure backward compatibility of the changes
• I have checked that my tests are not configured for a specific region or account (if appropriate)
• I have used unique_name_from_base to create resource names in integ tests (if appropriate)

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