bug: buildfunctions .f90 only, not .F90

[hkershaw-brown]

🐛 Your bug may already be reported!

Describe the bug

1. List the steps someone needs to take to reproduce the bug.
   Add some code you would like to build as part of dart:
   assimilation_code/modules/assimilation/cheesecake_filter_mod.F90

2. What was the expected outcome?
   That cheesecake_filter_mod.F90 would get included in the list of files to compile and then compiled in to dart (filter, pmo, whatever)

3. What actually happened?
   cheesecake_filter_mod.F90 is not found.

Error Message

/Users/hkershaw/DART/Bugs/issue_696/models/lorenz_96/cheesecake.f90:2:5:

    2 | use cheesecake_filter_mod
      |     1
Fatal Error: Cannot open module file 'cheesecake_filter_mod.mod' for reading at(1): No such file or directory
compilation terminated.

Which model(s) are you working with?

lorenz_96, but could be any.

Version of DART

Which version of DART are you using?
You can find the version using git describe --tags

Have you modified the DART code?

Yes, to give an example for .F90 code:
https://github.com/hkershaw-brown/DART/tree/bigF90

v11.6.0-1-g2a8903ca3

Build information

Please describe:

1. mac M2 (note case insensitive filesystem)
2. gnu

[hkershaw-brown]

also .f08? to use external code, e.g. https://github.com/dennisdjensen/fortran-testanything.git

[hkershaw-brown]

GSI2DART runs cpp as part of quickbuild.sh

DART/observations/obs_converters/GSI2DART/work/quickbuild.sh

Lines 30 to 32 in 464aa57

	# run the c preprocessor on enkf/kinds.F90
	\rm -f ../enkf/mykinds.f90
	cpp -P -D_REAL8_ -traditional-cpp ../enkf/kinds.F90 > ../enkf/mykinds.f90