ability to specify multiple pythonVersions

[DetachHead]

related: #7

Is your feature request related to a problem? Please describe.
as far as i can tell, there's no way to specify multiple python versions, so the following code will result in an unreachable code error:

if sys.version_info >= (3, 10):
    ...
else:
    ...

Describe the solution you'd like
option to specify pythonVersion as an array, or to just turn off the inspection entirely

Additional context

• our codebase can be run on either 3.9 or 3.10
• executionEnvironments seems to only allow you to specify parts of the project that run on different versions, but not multiple possible environments for the whole project
• Code is unreachable when testing for os.name microsoft/pylance-release#470 (comment)

rejected upstream issue: microsoft/pyright#2231