try to free up more space

.github/workflows/build.yml

@@ -29,8 +29,20 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      # free up some space
-      - run: sudo rm -rf /opt&
+      # The default disk size of these runners is ~14GB
+      # Cleanup the disk, see upstream discussion https://github.com/actions/runner-images/issues/2840.
+      - name: Cleanup Disk Space
+        run: |
+          echo "Before removing files:"
+          df -h
+          sudo rm -rf /usr/share/dotnet
+          sudo rm -rf /opt/ghc
+          sudo rm -rf /opt
+          sudo rm -rf "/usr/local/share/boost"
+          sudo rm -rf "$AGENT_TOOLSDIRECTORY"
+          echo "After removing files:"
+          df -h
+
       - uses: actions/checkout@v4
 
       - uses: DeterminateSystems/nix-installer-action@main