test explicit path to libomp instead

Author: siggmo

.github/workflows/build_and_test-mac.yaml

@@ -14,7 +14,7 @@ concurrency:
   cancel-in-progress: ${{github.event_name == 'pull_request'}}
 
 jobs:
-  build:
+  build-macOS:
     name: macOS 14 (M1)
     runs-on: macos-14
     env:
@@ -28,7 +28,7 @@ jobs:
       - name: Install FANS dependencies
         run: |
           brew install libomp cmake hdf5 openmpi eigen fftw
-          export OpenMP_ROOT=$(brew --prefix)/opt/libomp
+          export OpenMP_ROOT=/opt/homebrew/opt/libomp
 
       - name: Generate build directory
         run: mkdir -p ${{ env.FANS_BUILD_DIR }}