Python 3.12 support

[unoctanium]

Does transcrypt support python 3.12?

[JennaSys]

Not yet, however 3.12 will likely be the target version for the next major update. Because Transcrypt is intimately tied to the Python AST for transpiling, the version of Python is is fixed, and right now it is coded to use the version 3.9 AST.

That said, version 3.9 is only needed for transpiling the Python source code to JavaScript. If you also need to run the source code with CPython, you should still be able to do that with Python 3.12