Remove support for python versions 3.6 and 3.7 and ensure 3.10 and 3.11 are included

[antazoey]

Overview

Provide a simple overview of what you wish to see added. Please include:

• What you are trying to do
• Why solcx's current functionality is inadequate to address your goal

Specification

Describe the syntax and semantics of how you would like to see this feature implemented. The more detailed the better!

Remember, your feature is much more likely to be included if it does not involve any breaking changes.

[antazoey]

done