New example-c docs work to "Test the BMI" but breaks with pymt.models

[aufdenkampe]

@mcflugen & @mdpiper,

Thank you for merging this PR!

• Update C and Fortran docs examples #97

I was able to successfully (on a Mac) follow the Example: Wrapping a C model down to the Test the BMI section, but after that I got numerous errors, all related to pymt.

To make it work, I had to create a conda environment that built babelizer from the head of your develop branch, using this: https://github.com/LimnoTech/babelizer-examples/blob/main/environment.yml.

Given that pymt hasn't been updated since 2021, it might make sense to just put a big warning above that section of the docs, saying that pymt functionality is not currently compatible with the babelizer toolchain. That seems like a quick way to help folks avoid headaches.

@Volk3rJ & @ptomasula, can you try this workflow on Windows, down to Test the BMI](https://babelizer.readthedocs.io/en/latest/example-c.html#test-the-bmi)? Please do it from my modified environment.yml in https://github.com/LimnoTech/babelizer-examples

[mdpiper]

We just need to update pymt; it's 1) not built for Python 3.12, and 2) incompatible with recent changes to gimli.units.

[aufdenkampe]

Moving conversation on updating pymt to:

• pymt problems in Python > 3.9 pymt#167 (comment)

and closing here, as the example-c works well (on Mac) up to that point.