refactor(meson): update build to Fortran 2018 standard

[mjreno]

Update gfortran builds to use Fortran 2018 standard.

Checklist of items for pull request

• Replaced section above with description of pull request
• 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
• Removed checklist items not relevant to this pull request

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