chore: remove mac unit tests in library generation ci (#3142)

Fix: #2733 

The checks change to
<img width="735" alt="image"
src="https://github.com/user-attachments/assets/5b89dd78-2338-4412-93e1-6dc2ffdb487c">

Author: JoeWang1127

.github/workflows/verify_library_generation.yaml

@@ -73,21 +73,11 @@ jobs:
         set -x
         python -m unittest library_generation/test/integration_tests.py
   library-generation-unit-tests:
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-22.04
     needs: should-run-library-generation-tests
     if: needs.should-run-library-generation-tests.outputs.should_run == 'true'
-    strategy:
-      matrix:
-        java: [ 8 ]
-        os: [ ubuntu-22.04, macos-12 ]
     steps:
     - uses: actions/checkout@v4
-    - name: install utils (macos)
-      if: matrix.os == 'macos-12'
-      shell: bash
-      run: |
-        brew update --preinstall
-        brew install coreutils
     - uses: actions/setup-python@v5
       with:
         python-version: 3.11