Prevent llvm removal in test CI

.github/workflows/ci.yaml

@@ -52,13 +52,26 @@ jobs:
           rm --recursive --force "$AGENT_TOOLSDIRECTORY"
           df -h          
 
+          # remove large packages manually
+          sudo apt-get remove -y '^dotnet-.*'
+          sudo apt-get remove -y 'php.*'
+          sudo apt-get remove -y '^mongodb-.*'
+          sudo apt-get remove -y '^mysql-.*'
+          sudo apt-get remove -y azure-cli google-cloud-sdk google-chrome-stable firefox powershell mono-devel libgl1-mesa-dri
+          df -h          
+
       # Free up disk space on Ubuntu
       - name: Free Disk Space (Ubuntu)
         uses: jlumbroso/free-disk-space@main
         with:
           # This might remove tools that are actually needed, if set to "true" but frees about 6 GB
           tool-cache: false
-          large-packages: true
+
+          # large packages, except llvm, are removed manually during the previous step
+          # see: https://github.com/jlumbroso/free-disk-space/issues/6
+          # TODO: use the discussed whitelist feature when available
+          large-packages: false
+
           swap-storage: true
 
       - name: Checkout sources