feat(publish): change to use version from env var

[alissonperez]

What was done?

In this PR, the versioning system was changed to use the version from the environment variable. The __version__.py file was deleted and the version is now fetched from the environment variable in setup.py. Also, the Github workflow was updated to determine the version from the tag and pass it as an environment variable to the make publish command.

Maintaining __version__.py is not the best aproach here due to that it's easy to forget to change it before creating a release. It's better to just use an env var to fetch the right application version.

How was it done?

The changes were made in the setup.py file and the .github/workflows/release.yaml file. In setup.py, the version is now fetched from the environment variable. If the version is not found, an exception is raised. In the Github workflow, a new step was added to determine the version from the tag and pass it as an environment variable to the make publish command.

How was it tested?

The changes were tested by running the Github workflow and ensuring that the version is correctly fetched from the environment variable and the make publish command works as expected.