Remove brittle unit-test.

[1uc]

The removed test only checks if certain substrings are present. The golden testing automatically adds these tests for any usecase. Therefore, this test is not needed anymore.

The usecase for implementing non-specific current, will add a version of a passive current; and test the values against the analytical reference.

Ions are already covered by the ionic usecase.

Array variables are covered by the cnexp_array usecase.

Parameters coved by the parameters usecase.

Simple ODEs are covered by cnexp_* usecases.

[1uc]

While developing NRN support in NMODL, these tests are very annoying. I can never find the difference; and it's completely redundant with #1131. The CNRN variety can be revisited ater, since code generated for CNRN shouldn't be changing right now, it doesn't cause any issues.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 87.16%. Comparing base (c0eb1ac) to head (cb71564). Report is 1 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1172 +/- ## ========================================== - Coverage 88.38% 87.16% -1.23% ========================================== Files 176 176 Lines 12946 12890 -56 ========================================== - Hits 11442 11235 -207 - Misses 1504 1655 +151 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[bbpbuildbot]

Logfiles from GitLab pipeline #195923 (:white_check_mark:) have been uploaded here!

Status and direct links:

• :white_check_mark: spack_setup
• :white_check_mark: build:intel
• :white_check_mark: build:nvhpc
• :white_check_mark: test:intel
• :white_check_mark: test:nvhpc