typing.Self and Python versions

[devbisme]

InSpice is listed as working with versions of Python >=3.8. However, InSpice uses Self from the typing module and this did not appear until Python 3.11. Either the allowable Python version needs to be changed or some workaround made to accommodate the lack of typing.Self. (If possible, I would prefer the latter so that SKiDL can still perform SPICE simulations with older versions of Python.)

[tapegoji]

Thanks. Let me see what can be done.