chore: add free-disk-space action for integration tests

The tests all together generate large data.

This is especially the case for the cypthon buildpack.

Author: sgaist

.github/workflows/test-pull-request.yml

@@ -46,6 +46,19 @@ jobs:
         builder: ${{ fromJSON(needs.unit.outputs.builders) }}
       fail-fast: false  # don't cancel all test jobs when one fails
     steps:
+    - 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
+        # Default settings from documentation
+        android: true
+        dotnet: true
+        haskell: true
+        large-packages: true
+        docker-images: true
+        swap-storage: true
     - name: Setup Go
       uses: actions/setup-go@v3
       with: