use GLw from homebrew

.github/workflows/macos.yml

@@ -33,7 +33,7 @@ jobs:
       # Note the current convention is to use the -S and -B options here to specify source 
       # and build directories, but this is only available with CMake 3.13 and higher.  
       # The CMake binaries on the Github Actions machines are (as of this writing) 3.12
-      run: cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE
+      run: cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE -DINVENTOR_INTERNAL_GLW=FALSE
 
     - name: Build
       working-directory: ${{runner.workspace}}/build