stellar#4538: create free space on gh runner for verify-range due to out of space

Author: sreuland

.github/workflows/horizon.yml

@@ -126,6 +126,10 @@ jobs:
       STELLAR_CORE_VERSION: 21.3.1-2007.4ede19620.focal
       CAPTIVE_CORE_STORAGE_PATH: /tmp
     steps:
+      - name: Free Disk Space (Ubuntu)
+        uses: jlumbroso/free-disk-space@main
+        with:
+          tool-cache: true
       - uses: actions/checkout@v3
         with:
           # For pull requests, build and test the PR head not a merge of the PR with the destination.