Add release workflow

[rasbt]

As discussed in #1348 @carmocca, this is a workflow for publishing to PyPI. I used this previously in my BioPandas package, and it worked great. You basically just need to add the PyPI API tokens as described here https://dev.to/iamtekson/publish-package-to-pypi-and-release-new-version-using-github-actions-108k

Fixes #1348

[Learneducn]

Hello, excuse me. When I follow the tutorial and use your script "convert_lit_checkpoint.py" to convert the llama-2-7b-hf model, the following error always appears. I don’t know how to solve it.

[root@localhost RobustGER-master]# sh conv_model.sh usage: convert_lit_checkpoint.py [-h] [--config CONFIG] [--print_config[=flags]] --checkpoint_name CHECKPOINT_NAME --out_dir OUT_DIR --model_name MODEL_NAME error: Validation failed: No action for key "_name_or_path" to check its value.

[rasbt]

Unfortunately I don't have access to that, but @lantiga can maybe help here since he also made the past LitGPT releases when I remember correctly

[carmocca]

Merging. I'll add my own token and try it out

[carmocca]

Worked flawlessly: https://github.com/Lightning-AI/litgpt/actions/runs/8999883396/job/24722989843, https://pypi.org/project/litgpt/#history

Thanks Seb!

[rasbt]

Awesome, glad to hear!