Minimum Python version for Basilisk is 3.8 and not 3.7

[patkenneally]

Describe the bug
In practice the minimum Python version for basilisk is 3.8, yet the build system checked for 3.7. A few people have fallen victim to this.

To reproduce
Steps to reproduce the behavior:

1. Try and use Basilisk with Python 3.7. It won't work because the project uses type hinting.

Expected behavior
NA because I'm advocating that the 3.7 be left behind. This work updated the CMakeList and conanfile to check for 3.8. There is no real value in trying to support 3.7 (no ability to provide type hints which is the main feature which cause 3.7 to fail). Further 3.7 is now end-of-life. For reference https://devguide.python.org/versions/

Screenshots
NA

Desktop (please complete the following information):

• OS: Macos
• Version 13.6.2
• Python version 3.10.9

Additional context
NA