fix: format statement in assert_mod

Description:

Fix for format statement in assert_mod. The goal of putting in this seemingly inconsequential change in is so the NAG compiler can be used to build dart, and not error out on this.

The other NAG build error is fixed in #588.

Fixes issue

fixes nag compiler (item 2) #615

Types of changes

[x] Bug fix (non-breaking change which fixes an issue)
[ ] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
[ ] Documentation update

Documentation changes needed?

[ ] My change requires a change to the documentation.
- [ ] I have updated the documentation accordingly.

Tests

Please describe any tests you ran to verify your changes.

program test_assert

use assert_mod, only : assert_equal_logical_array

implicit none

logical :: a(3), b(3)

a(:) = .true.
b(:) = .false.

call assert_equal_logical_array(a,b, 'beans on toast')

end program test_assert

add test_assert to serial_programs in quickdbuild.sh

./quickdbuild.sh test_assert
./test_assert

Checklist for merging

[ ] Updated changelog entry
[ ] Documentation updated
[ ] Update conf.py

Checklist for release

[ ] Merge into main
[ ] Create release from the main branch with appropriate tag
[ ] Delete feature-branch

Testing Datasets

[ ] Dataset needed for testing available upon request
[ ] Dataset download instructions included
[ ] No dataset needed

NCAR / DART

fix: format statement in assert_mod #618