Comment out Metis

.github/workflows/build-special.yml

@@ -132,9 +132,10 @@ jobs:
         if: matrix.flag == 'system'
         run: |
           sudo apt-get install libeigen3-dev
-          sudo apt-get install metis
           echo "GTSAM_USE_SYSTEM_EIGEN=ON" >> $GITHUB_ENV
-          echo "GTSAM_USE_SYSTEM_METIS=ON" >> $GITHUB_ENV
+          # TODO(dellaert): This does not work yet?
+          # sudo apt-get install metis
+          # echo "GTSAM_USE_SYSTEM_METIS=ON" >> $GITHUB_ENV
 
       - name: Build & Test
         run: |