Add python 3.11 support (and drop 3.7)

[staticdev]

This PR makes some major changes:

• Adds support to Python 3.11
• Enables Safety as dependency checker for security.
• Fixes broken dependency tree to fix security issues pointed by Safety.
• Removes support for Python 3.7 (it is conflicting with newer versions of sphinx/flake8 due to lack of importlib.metadata).

[Cube707]

confimed working on my machine

(Win 10, python 3.10.6)

[staticdev]

@magmax LGTM?

[staticdev]

I will consider silence a consent.