Specify which Python versions are supported

[torbsorb]

Clarify exactly which Python versions are supported, and add the classifiers that makes it clear in the sidebar on pypi.org.

[SatjaSivcev]

Not sure what I want with this, but have in mind that we also state which python we support here https://support.zivid.com/en/latest/api-reference/sdk-lifecycle.html#python depending on the OS. Take it into consideration when deciding what is the best for this PR, to avoid any confusion.