refactor(TspSpc.f90): extend spc utility usage to gwe

[emorway-usgs]

The SPC utility for SSM works for CONCENTRATION arrays in GWT, but not for TEMPERATURE arrays in GWE. Refactor facilitates use of the SPC utility with GWE's SSM package.

Checklist of items for pull request

• Replaced section above with description of pull request
• Added new test or modified an existing test
• Ran ruff on new and modified python scripts in .doc, autotests, doc, distribution, pymake, and utils subdirectories.
• Formatted new and modified Fortran source files with fprettify
• Added doxygen comments to new and modified procedures
• Updated meson files, makefiles, and Visual Studio project files for new source files
• Updated definition files
• Updated develop.tex with a plain-language description of the bug fix, change, feature; required for changes that may affect users
• Updated input and output guide

[langevin-usgs]

Looks like this is close. Any thoughts on the failures, @emorway-usgs?

[emorway-usgs]

Looks like this is close. Any thoughts on the failures, @emorway-usgs?

Running build_makefiles.py on Windows switches the / to \ in the paths. Being a little out of practice, I forgot to switch 'em back after running the script.