Test package uploading to PyPI before releasing and creating a new version tag

[IshaanDesai]

Currently, we run the release workflow to upload the package to PyPI after creating a tag on GitHub, which is typically associated with a newly released version. If the release workflow fails, it is too late to make corrections since the release is complete and the tag has been created. Testing whether the release workflow works before actually releasing a new version would be helpful.

The PyPI Publish GitHub Action usage states that packages can be pushed to the instance TestPyPI. An additional workflow can be added which uploads the package to TestPyPI, to test the release workflow, and also the creation of distribution archives before releasing a new version