Support for ISP Workbook version 7.5

[James-Aylward]

Adds configuration for ISP workbook version 7.5, used in "Draft 2026 ISP Inputs and Assumptions workbook".

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[nick-gorman]

Thanks for PR @James-Aylward!

These updates can be a bit of a slog, so definitely appreciate the help.

Looked pretty good to me, I've just added in some extra tables and fixed some names up.

We are running into errors for the extra tables on macos though. @EllieKallmier any chance you could use your Mac to dig a bit deeper on this? It looks like on mac the table distribution_network_CER_augmentation_tranche_costs in workbook 7.5 has data after the last row, but this isn't showing up on windows.

[nick-gorman]

Thanks for PR @James-Aylward!

These updates can be a bit of a slog, so definitely appreciate the help.

Looked pretty good to me, I've just added in some extra tables and fixed some names up.

We are running into errors for the extra tables on macos though. @EllieKallmier any chance you could use your Mac to dig a bit deeper on this? It looks like on mac the table distribution_network_CER_augmentation_tranche_costs in workbook 7.5 has data after the last row, but this isn't showing up on windows.

Turns out the macos error was a bug caused by configs with dupilcate names, which only showed up on macos because the config loading order was different. The bad config loaded first on mac and was used while on windows the good config was used. Changing the name of the second config and pointing it at the correct workbook sheet solved this issue.