Remove unused matrix variables

Author: penelopeysm

.github/workflows/CI.yml

@@ -44,9 +44,6 @@ jobs:
       - uses: julia-actions/julia-buildpkg@v1
 
       - uses: julia-actions/julia-runtest@v1
-        env:
-          GROUP: ${{ matrix.test_group }}
-          JULIA_NUM_THREADS: ${{ matrix.runner.num_threads }}
 
       - uses: julia-actions/julia-processcoverage@v1