Try to cancel a running CI job

.github/workflows/unit_tests.yaml

@@ -174,6 +174,7 @@ jobs:
           spack unit-test -k 'not cvs and not svn and not hg' -x --verbose
   # Test for the clingo based solver (using clingo-cffi)
   clingo-cffi:
+    if: ${{ inputs.with_coverage == 'false' }}
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b # @v2
@@ -219,6 +220,7 @@ jobs:
         flags: unittests,linux,clingo
   # Run unit tests on MacOS
   macos:
+    if: ${{ inputs.with_coverage == 'false' }}
     runs-on: macos-latest
     strategy:
       matrix: