Use classifiers to specify license

[William-Wolke]

Type of change

• New feature
• Bug fix
• Security patch
• Documentation update

Description

When this repo moved to using pyproject.toml it intoduced a bug for libraries like pip-licenses to properly determine the licese of this project. Since the file used to determine the license: license = { file = "./LICENSE" } is not standard due to extra text in front of the Copyright block

To fix this issue we can use classifiers to set the license for the package.

Motivation

This pr fixes issues for others using pip-licenses to check for licenses in their dependencies

Checklist

• I have read the CONTRIBUTING document.
• I have read and accepted the Code of conduct
• Tests passes.
• Style lints passes.
• Documentation of new public methods exists.

[dannyhajj]

Thanks for the fix!