Enable compatibility with NREL-PySAM v6 and v7

[misi9170]

Currently, Hercules requires NREL-PySAM v6. However, v7 was released in April 2025 and the latest version is v7.1.0 (released August 2025).

Hercules, as is, is not compatible with v7 of NREL-PySAM. This "fixes" this by adding a couple of try/except clauses on a few lines that generate errors. However, I am not sure if this is a legitimate fix or if I am changing the behavior.

With the update:

• tests pass using both v6.0.1 and v7.1.0
• example 03_wind_and_solar runs to completion and produces visually the same result:

Using v6.0.1:

Using v7.1.0:

Assuming we no longer need to use the lines that are excepted in this change, we could simply require v7. However, this is a change that will affect users directly, as they'll need to update their local environments to keep using Hercules. The change I've implemented here allows users to stay on v6, or to move up to v7.

If a valid correction, addresses #218

[paulf81]

I think that could work, I think I added those lines when tinkering with this module and not sure how critical. Maybe @brookeslawski would you mind to give this change a look over?

[elenya-grant]

if you want to keep backward compatibility with PySAM v6 you could do:

import PySAM

if int(PySAM.__version__.split(".")[0]) < 7:
   system_model.AdjustmentFactors.dc_adjust_constant = 0

instead of the try-except

[misi9170]

Going to see whether running with v6 with these lines just removed still passes tests

[misi9170]

Ok, I've now simply removed the two lines that caused issues. Tests still pass, and example 03 still provides (visually) the same output, so perhaps that's good enough?